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

This is a new screencopy protocol which improves upon wlr-screencopy-unstable-v1.

Supersedes: !39 (closed)

• Review
• 2 ACKs
  • wlroots (@emersion)
  • COSMIC (@Drakulix)
• 2 implementations
  • wlroots: wlroots/wlroots!4545 (merged)
  • wayvnc: https://github.com/any1/wayvnc/tree/ext-screencopy-v1
  • grim: https://git.sr.ht/~emersion/grim/log/ext-screencopy-v1

.gitlab/merge_request_templates/New protocol.md

+
+
+#### Requirements for merging
+
+- [ ] Review
+- [ ] Implementations
+- [ ] ACKs from members
+
+/label ~"New Protocol" ~"In 30 day discussion period" ~"Needs acks" ~"Needs implementations" ~"Needs review"