OO-1346: use a query to load a specific message to prevent EntityNotFoundException if the message was deleted

	OO-1253: not assessable nodes and not published nodes return a score of 0.0 instead of the large negative number. If not assessed, no score seems logic but not a large negative value

OO-1342: refactor the loading mechanism for the custom media controller with a standard factory pattern

OO-1341; make the extension of the image mandatory, needed by the java scaling service to discover the type of the image

OO-1322: fix an issue if several different types is found for the uploaded resources and the import is restricted to a type of resources