This moves the remaining `.c` files in the following `editors` folders to C++:
`physics`, `screen`, `sound`, `space_buttons`, `space_file`, `space_graph` and `space_image`.
One exception is `fsmenu.c` which has platform specific issues on macos and
windows. E.g. the `Carbon/Carbon.h` include also declares a `Collection` type that collides
with ours.
Also see #103343.
Pull Request: https://projects.blender.org/blender/blender/pulls/109918
