Fix focus loss on macOS.

[bruvzg]

Fixes #43675.

Regression form #42276, removed line works when app is started from terminal, but cause app to minimize on start if bundled. Removing it means that app with --no-window will steal focus form terminal / parent process, but with the current way Godot is handling command line arguments unlikely there's a way to do it better.

Probably we need to split argument parsing to have stuff like no-window before OS init.

1. Parse arguments for OS init.
2. Init OS.
3. Parse arguments for opening files/projects (in case of macOS, argument list can be changed by OS init, macOS is handling file associations in openFile: app delegate callback instead of command line).
4. Init DisplayServer, Audio, etc. and load project.

[RandomShaper]

Looks good to me.

The focus stealing issue can be addressed separately if it turns out to be too annoying for users.

[akien-mga]

Thanks!