Happy new year to the wonderful Godot community!
We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.
Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
ResourceFormatLoader and ResourceFormatSaver are meant to be overridden
to add support for different formats in ResourceLoader and ResourceSaver.
Those should be exposed as they can be overridden in plugins.
On the other hand, all predefined subclasses of those two base classes
are only meant to register support for new file and resource types, but
should not and cannot be used directly from script, so they should not
be exposed.
Also unexposed ResourceImporterOGGVorbis (and thus its base class
ResourceImporter) which are editor-only.
