Git: Adopt editor in SCM input

[joaomoreno]

The Monaco editor can be used as the SCM input widget

[skarcha]

It'd cool that commit message editor breaks lines at defined line size (for example, 72). And fixed width font, please! :-)

[joaomoreno]

Actually, reverting #84201 or implementing #6403 isn't dependent on this. Will change this feature request to adopt the editor in the scm input.

@skarcha #2718