src: code cleanup

* removed unused code: ParseFunction, ParseVariable and ParseTypeUsage. All this is handled using NameHierarchies now.
* Moved the getErrorCount method from ParserClient to the StorageAccess
* MessageFinishedParsing doesn't know the error count anymore.
* StatusBarController now has a StorageAccess to fetch the error count when needed.

src/lib/data/access/StorageAccess.h

@@ -10,6 +10,7 @@
 
 #include "data/graph/Node.h"
 #include "data/search/SearchMatch.h"
+#include "data/ErrorCountInfo.h"
 #include "data/StorageStats.h"
 
 struct FileInfo;
@@ -62,6 +63,7 @@ public:
 	virtual std::shared_ptr<TextAccess> getFileContent(const FilePath& filePath) const = 0;
 	virtual TimePoint getFileModificationTime(const FilePath& filePath) const = 0;
 
+	virtual ErrorCountInfo getErrorCount() const = 0;
 	virtual StorageStats getStorageStats() const = 0;
 };