Reverting main branch to pre-openxr build

Update 29.1 - reverting to preopenXR build for the main branch

Due to some technical issues experienced by our users, we are reverting the main branch back to the pre-openXR branch. This will be a few updates of rollback, however it will allow users to experience Gun World VR without the glitches of openXR.

For those who want to continue on with the openXR branch, please switch to the alpha1 branch, which includes all recent updates.