[libcalamares] TZRegion is hard to copy

- delete the copy and move constructors
 - adjust tests (which were just interested in simple tr() behavior) to use TZZone instead

src/libcalamares/locale/Tests.cpp

@@ -215,12 +215,12 @@ LocaleTests::testSimpleZones()
         QVERIFY( n.tr().isEmpty() );
     }
     {
-        TZRegion r0( "xAmsterdam" );
+        TZZone r0( "xAmsterdam" );
         QCOMPARE( r0.tr(), QStringLiteral( "xAmsterdam" ) );
-        TZRegion r1( r0 );
+        TZZone r1( r0 );
         QCOMPARE( r0.tr(), QStringLiteral( "xAmsterdam" ) );
         QCOMPARE( r1.tr(), QStringLiteral( "xAmsterdam" ) );
-        TZRegion r2( std::move( r0 ) );
+        TZZone r2( std::move( r0 ) );
         QCOMPARE( r2.tr(), QStringLiteral( "xAmsterdam" ) );
         QCOMPARE( r0.tr(), QString() );
     }

src/libcalamares/locale/TimeZone.h

@@ -89,6 +89,7 @@ class TZRegion : public CStringPair
 public:
     using CStringPair::CStringPair;
     virtual ~TZRegion() override;
+    TZRegion( const TZRegion& ) = delete;
     QString tr() const override;
 
     QString region() const { return key(); }