1.2.0 is going to be the first version with 1.19.3 support. Will require support for mc-vr-api on 1.19.3

Initial branch is up https://github.com/hammy3502/immersive-mc/tree/1.19.3 . Still need to do testing with VR and port mc-vr-api up to 1.19.3.

That being said, it looks like it won't take much to maintain both 1.19.3 and 1.19.2, so I'll be doing that going forward. Besides bugfixes, 1.2.0 will be the last release for 1.18.2

mc-vr-api port is done