The last remaining ERR_EXPLAIN call is in FreeType code and makes sense as is
(conditionally defines the error message).
There are a few ERR_EXPLAINC calls for C-strings where String is not included
which can stay as is to avoid adding additional _MSGC macros just for that.
Part of #31244.
This allows more consistency in the manner we include core headers,
where previously there would be a mix of absolute, relative and
include path-dependent includes.
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
-Added default environment editor setting
-Added environment created by default in new projects
-Removed default light and ambient from spatial editor, to make the editor more PBR compliant
