[openxr] Handle input/output structures automatically in codegen

[MarkY-LunarG]

In OpenXR, there are several structures that are filled in by various API calls that require some initialization before being passed in. The initialization includes, setting values appropriately (beyond type and next) such as counts and array memory allocations. These should be handled automatically in code gen.

Currently there are two locations that need to be code generated appropriately:

1. The API call itself which handles such a structure

• This includes at least the following APIs that are hand generated right now in openxr_replay_consumer_base.cpp (prepended with Process_):
  • xrLocateSpaces
  • xrLocateHandJointsEXT
  • xrGetMeshFB
  • xrLocateBodyJointsEXT

2. next chain structures that are handled in such a wa:

• This includes at least the following structures that are hand generated right now in openxr_replay_consumer_base.cpp (prepended with OverrideOutputStructNext_):
  • XrSpaceVelocities
  • XrHandJointVelocitiesEXT