Until now, the `RealmContextFactory` would be disposed as part of the
drawable hierarchy. This is too early, as it may be being used by higher
level components (like `ConfigManager`s, see #15115) that perform final
operations after the drawables have been disposed.
Seems to make sense moving this out of the drawable hierarchy and in
line with how we were doing things with EF.
Only the file related ones are really required outside of tests, but
seems like as good an opportunity as ever to get the rest of the models
into the game project.