ui: scope names in snippet titles

* added title for snippets
* title displays name of parent scope.
* when new TokenLocationFiles are created in the storage they are now returned as shared_ptr to ensure correct linking in the contained data.
* Storage::getTokenLocationsForLinesInFile() now always returns pairs of start and end locations.
* Adjusted code snippet view to regard the change described above.

src/app/qt/element/QtCodeFileList.h

@@ -24,8 +24,9 @@ public:
 
 	void addCodeSnippet(
 		uint startLineNumber,
+		const std::string& title,
 		const std::string& code,
-		const TokenLocationFile& locationFile
+		std::shared_ptr<TokenLocationFile> locationFile
 	);
 
 	void clearCodeSnippets();