Blender Git Commit Log

Add some asset engine-aware stuff in filebrowser.

Basically, filelisting code in space_file becomes default, internal 'asset engine',
and user can switch to any other available engine instead.

Note filelisting with asset engines is fully main-thread from C code PoV,
parallelization/asynchronism is responsability of the py code!

Also, added a basic (dummy currently) AssetEngine py implementation.
Not much there, but helps checking things works as expected before
writing whole interface!

All this is very basic early code yet, much much to do before we get anything really usable...