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/project/SourceGroup.h

@@ -0,0 +1,38 @@
+#ifndef SOURCE_GROUP_H
+#define SOURCE_GROUP_H
+
+#include <memory>
+#include <set>
+#include <vector>
+
+#include "utility/file/FilePath.h"
+#include "settings/LanguageType.h"
+#include "settings/SourceGroupType.h"
+
+class IndexerCommand;
+
+class SourceGroup
+{
+public:
+	virtual ~SourceGroup();
+
+	virtual SourceGroupType getType() const = 0;
+	LanguageType getLanguage() const;
+
+	virtual bool prepareRefresh();
+	virtual bool prepareIndexing();
+
+	virtual void fetchAllSourceFilePaths() = 0;
+	void fetchSourceFilePathsToIndex(const std::set<FilePath>& staticSourceFilePaths);
+
+	std::set<FilePath> getAllSourceFilePaths() const;
+	std::set<FilePath> getSourceFilePathsToIndex() const;
+
+	virtual std::vector<std::shared_ptr<IndexerCommand>> getIndexerCommands(const bool fullRefresh) = 0;
+
+protected:
+	std::set<FilePath> m_allSourceFilePaths;
+	std::set<FilePath> m_sourceFilePathsToIndex;
+};
+
+#endif // SOURCE_GROUP_H