Repaths /obj/screen into /atom/movable/screen

[ChesterTheCheesy]

Document the changes in your pull request

Does what tg did in https://github.com/tgstation/tgstation/pull/54403.

Should improve performance when loading screen objects (like damage overlays which for some reason lag you for 3-5 seconds).

I tested this on my own server, and it does make a slight difference.

Changelog

:cl:
tweak: should improve performance by repathing screen objects into a more basic format /:cl:

[TheGamerdk]

I think this should only make a difference for memory usage? Good change either way