REUSE: use <author> tag in .ui for license info

The .ui files are all GPL-3.0-or-later style, but it's
slightly difficult to keep licensing information in them:
it's XML, so an XML comment might work, but there's no
guarantee that safe/load will preserve them.

Put the SPDX tags in the <author> tag, so that it's visible
in Qt Designer.

src/calamares/DebugWindow.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2015 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>Calamares::DebugWindow</class>
  <widget class="QWidget" name="Calamares::DebugWindow">
   <property name="geometry">
@@ -52,7 +56,7 @@
          <item>
           <layout class="QFormLayout" name="formLayout">
            <item row="0" column="0">
-            <widget class="QLabel" name="label">
+            <widget class="QLabel" name="typeLabel">
              <property name="text">
               <string>Type:</string>
              </property>
@@ -66,7 +70,7 @@
             </widget>
            </item>
            <item row="1" column="0">
-            <widget class="QLabel" name="label_2">
+            <widget class="QLabel" name="interfaceLabel">
              <property name="text">
               <string>Interface:</string>
              </property>

src/modules/finished/FinishedPage.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2015 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>FinishedPage</class>
  <widget class="QWidget" name="FinishedPage">
   <property name="geometry">

src/modules/keyboard/KeyboardPage.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>Page_Keyboard</class>
  <widget class="QWidget" name="Page_Keyboard">
   <property name="geometry">

src/modules/license/LicensePage.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2015 demmm &lt;anke62@gmail.com&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>LicensePage</class>
  <widget class="QWidget" name="LicensePage">
   <property name="geometry">

src/modules/netinstall/page_netinst.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2016 shainer &lt;syn.shainer@gmail.com&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>Page_NetInst</class>
  <widget class="QWidget" name="Page_NetInst">
   <property name="geometry">

src/modules/oemid/OEMPage.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2019 Adriaan de Groot &lt;groot@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>OEMPage</class>
  <widget class="QWidget" name="OEMPage">
   <property name="geometry">

src/modules/packagechooser/page_package.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2019 Adriaan de Groot &lt;groot@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>PackageChooserPage</class>
  <widget class="QWidget" name="PackageChooserPage">
   <property name="geometry">

src/modules/partition/gui/ChoicePage.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2015 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>ChoicePage</class>
  <widget class="QWidget" name="ChoicePage">
   <property name="geometry">

src/modules/partition/gui/CreatePartitionDialog.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Aurélien Gâteau &lt;agateau@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>CreatePartitionDialog</class>
  <widget class="QDialog" name="CreatePartitionDialog">
   <property name="geometry">

src/modules/partition/gui/CreatePartitionTableDialog.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Aurélien Gâteau &lt;agateau@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>CreatePartitionTableDialog</class>
  <widget class="QDialog" name="CreatePartitionTableDialog">
   <property name="geometry">

src/modules/partition/gui/EditExistingPartitionDialog.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Aurélien Gâteau &lt;agateau@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>EditExistingPartitionDialog</class>
  <widget class="QDialog" name="EditExistingPartitionDialog">
   <property name="geometry">

src/modules/partition/gui/EncryptWidget.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2016 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>EncryptWidget</class>
  <widget class="QWidget" name="EncryptWidget">
   <property name="geometry">

src/modules/partition/gui/PartitionPage.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Aurélien Gâteau &lt;agateau@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>PartitionPage</class>
  <widget class="QWidget" name="PartitionPage">
   <property name="geometry">

src/modules/partition/gui/ReplaceWidget.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>ReplaceWidget</class>
  <widget class="QWidget" name="ReplaceWidget">
   <property name="geometry">

src/modules/partition/gui/VolumeGroupBaseDialog.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2018 Caio &lt;caiojcarvalho@gmail.com&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>VolumeGroupBaseDialog</class>
  <widget class="QDialog" name="VolumeGroupBaseDialog">
   <property name="geometry">

src/modules/plasmalnf/page_plasmalnf.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2017 Adriaan de Groot &lt;groot@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>PlasmaLnfPage</class>
  <widget class="QWidget" name="PlasmaLnfPage">
   <property name="geometry">

src/modules/tracking/page_trackingstep.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2017 Adriaan de Groot &lt;groot@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>TrackingPage</class>
  <widget class="QWidget" name="TrackingPage">
   <property name="geometry">

src/modules/users/page_usersetup.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>Page_UserSetup</class>
  <widget class="QWidget" name="Page_UserSetup">
   <property name="geometry">

src/modules/welcome/WelcomePage.ui

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
+ <author>
+SPDX-FileCopyrightText: 2014 Teo Mrnjavac &lt;teo@kde.org&gt;
+SPDX-License-Identifier: GPL-3.0-or-later
+ </author>
  <class>WelcomePage</class>
  <widget class="QWidget" name="WelcomePage">
   <property name="geometry">