[libcalamaresui] Move RequirementsChecker to libcalamares

- the checker only collects and calls requirements; it has no
  UI component, and only manages data (and a thread to do the
  checking). Move it out of the UI library.

src/libcalamares/CMakeLists.txt

@@ -41,6 +41,7 @@ set( libSources
     modulesystem/InstanceKey.cpp
     modulesystem/Module.cpp
     modulesystem/Requirement.cpp
+    modulesystem/RequirementsChecker.cpp
 
     # Network service
     network/Manager.cpp

src/libcalamares/modulesystem/RequirementsChecker.h

@@ -25,7 +25,6 @@
 #include <QTimer>
 #include <QVector>
 
-
 namespace Calamares
 {
 
@@ -44,7 +43,7 @@ public:
     RequirementsChecker( QVector< Module* > modules, QObject* parent = nullptr );
     virtual ~RequirementsChecker() override;
 
-public slots:
+public Q_SLOTS:
     /// @brief Start checking all the requirements
     void run();
 

src/libcalamaresui/CMakeLists.txt

@@ -9,7 +9,6 @@ set( calamaresui_SOURCES
     modulesystem/ModuleFactory.cpp
     modulesystem/ModuleManager.cpp
     modulesystem/ProcessJobModule.cpp
-    modulesystem/RequirementsChecker.cpp
     modulesystem/ViewModule.cpp
 
     utils/CalamaresUtilsGui.cpp

src/libcalamaresui/modulesystem/ModuleManager.cpp

@@ -19,11 +19,11 @@
 
 #include "ModuleManager.h"
 
-#include "RequirementsChecker.h"
-#include "Settings.h"
 #include "ViewManager.h"
 
+#include "Settings.h"
 #include "modulesystem/Module.h"
+#include "modulesystem/RequirementsChecker.h"
 #include "utils/Logger.h"
 #include "utils/Yaml.h"
 #include "viewpages/ExecutionViewStep.h"