data: reduced size of generated .coatidb files

* added occurrence table to get rid of duplicate source locations
* reverted storage provider

src/lib/data/parser/ParserClientImpl.cpp

@@ -293,8 +293,7 @@ void ParserClientImpl::addSourceLocation(Id elementId, const ParseLocation& loca
 		return;
 	}
 
-	m_storage->addSourceLocation(
-		elementId,
+	Id sourceLocationId = m_storage->addSourceLocation(
 		addFile(location.filePath.str()),
 		location.startLineNumber,
 		location.startColumnNumber,
@@ -302,6 +301,11 @@ void ParserClientImpl::addSourceLocation(Id elementId, const ParseLocation& loca
 		location.endColumnNumber,
 		type
 	);
+
+	m_storage->addOccurrence(
+		elementId,
+		sourceLocationId
+	);
 }
 
 void ParserClientImpl::addComponentAccess(Id nodeId , int type)