Add async AER extra eye copy for OpenXR in D3D11Component

[mutars]

Summary

This change adds support for asynchronous Asynchronous Eye Reprojection (AER) in the D3D11 VR component by performing additional eye texture copies when async AER is enabled.

Key Changes

• After copying the left eye to OpenXR, if async AER is enabled, also copy the right eye texture
• After copying the right eye to OpenXR, if async AER is enabled, also copy the left eye texture
• Both extra copies use the appropriate texture source (8-bit or render target based on backbufferIs8Bit flag)
• Added verbose logging to distinguish the extra async AER copies from standard eye copies

Implementation Details

• The extra copies are only performed when vr->is_using_async_aer() returns true
• Each extra copy respects the existing texture format selection logic (8-bit vs render target)
• The changes are minimal and non-invasive, adding conditional logic only when async AER is active
• This ensures both eye textures are available to OpenXR for proper async reprojection handling

https://claude.ai/code/session_0113R4SbhVpihniGsyFqv6vP