The open source OpenXR runtime

doc: Document !1894

+4
+1
doc/changes/auxiliary/mr.1894.md
··· 1 + vk: Add and use enumeration helpers.
+2
doc/changes/compositor/mr.1894.1.md
··· 1 + util: Use enumeration helpers, with a tiny little bit of refactor to increase 2 + code reuse.
+1
doc/changes/compositor/mr.1894.2.md
··· 1 + main: Use enumeration helpers in and refactor the NVIDIA direct target code.