implement ext-image-capture-source-v1 and ext-image-copy-capture-v1

[ikalco]

protocols links:
ext-image-capture-source-v1
ext-image-copy-capture-v1

Some clients are starting to use this now, so it might be worth implementing (wlroots has)

wayvnc, Implement ext-image-copy-capture-v1
grim, Add support for ext-image-copy-capture-v1
quickshell, wayland/screencopy: add screencopy
wl-screenrec, #82: ext image cap

[vaxerski]

yes, agreed. I'll want to add a screencopy permission system first, though.

[vaxerski]

promoted #9916 and #9915