macos: use display id when creating CVDisplayLink

macos: use display id when creating CVDisplayLink

Currently we're using a display link that is for all active displays which
is just the display server trying to find some timings that try to overlap
as many as possible.

That was fine for a prototype, but we really need to do better for
situations with mixed frame rate (such as 60hz and 120hz promotion
displays). Additionally, the 144hz external monitor I have will never
reach 144hz using the current design.

This is just the first step in changing this, but the goal is to have
one of these attached to each GdkMacosMonitor which we can then use to
thaw surfaces specific to that monitor.