resourceloader: Keep module_deps handling inside module base class
Most of it was already there (SELECT in preloadInfo, and in-class holder via
setFileDependencies) but the logic to write to the database was within
the file module class.
Moving it the other way around may make more sense in the future, but for
the moment ResourceLoader.php makes assumptions about all modules being
able to store setFileDependencies as read from the database. Whether or not
a class currently implements a way to write to that table.
Change-Id: I06b5da4144798197478c66e8b9ccd4cc62cf6fb6