[macOS] Enable code signing by default, use ad-hoc signature if no identity specified.
[macOS] Enable code signing by default, use ad-hoc signature if no identity specified.

(cherry picked from commit 09c8e69232ff5ec0c72c80d8b48168545876d5d4)

ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot,ex/godot