logic: source groups for project settings

* project can not have multiple source groups with different types
* language of a project is now inferred from source groups
* setting global NameHierarchy delimiter of first sourceGroup in project
* added project settings migrations for source groups
* Add Settings Migration classes (MoveKey, DeleteKey, Lambda)
* Update sample projects with migrations
* added method to config to retrieve sublevel key names
* implemented recursive removing of keys in settings
* moved project files out of top level
* removed solution parsing code as it is not used anymore

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src/lib/settings/Settings.h

@@ -8,7 +8,8 @@
 #include "utility/ConfigManager.h"
 #include "utility/file/FilePath.h"
 
-#include "settings/SettingsMigrator.h"
+#include "settings/migration/SettingsMigrator.h"
+#include "settings/migration/Migration.h"
 
 class Settings
 {
@@ -65,6 +66,9 @@ protected:
 
 private:
 	FilePath m_filePath;
+
+	friend SettingsMigrator;
+	friend Migration;
 };
 
 template<typename T>