This commit brings multi-monitor window positioning support to the macOS
GHOST backend. This fixes a plethora of issues with macOS window
creation and positioning, such as:
* Windows not being properly restored when loading a file with Load UI
* Users default startup windows not being properly restored on multiple
screens
* Temporary windows (Settings, Render, Playblast, etc..) wrongly
appearing in unexpected places / other screens
* Duplicating an area into a new window (AKA popping out an editor) not
working on non-primary screens.
* etc..
Internally, this makes all macOS windows coordinates be relative to the
user primary monitor, instead of being local to the currently focused
one. I have tested this to properly work using all sorts of multiple
screen arrangements, and can also confirm that restoring windows from
screens that do not exist anymore / are now out of bounds (due to being
unplugged or re-arranged) also works properly, in which case they get
snapped back to the closest available screen similarly to other backends.
This fixes issue #126410 and implements behavior described in TODO task #69819.
Pull Request: https://projects.blender.org/blender/blender/pulls/141159
b0ffd4cb07