Implement GX Thread for Asynchronous Rendering

- Introduced a new GX thread to handle the rendering pipeline, allowing the game thread to post commands without blocking.
- Added `gx_thread.h` and `gx_thread.cpp` to manage the command ring buffer and thread synchronization.
- Updated `vi.cpp` to utilize the GX thread for rendering tasks, improving frame pacing and responsiveness.
- Modified `main.cpp` to configure and start the GX thread, ensuring it integrates with the existing rendering workflow.
- Enhanced `openxr_integration.cpp` to register the GX thread with OpenXR for better performance in VR scenarios.
- Refactored `settings_overlay.cpp` to remove unnecessary waits for the frame worker, as the overlay now draws directly into the game thread's ImGui frame.
- Improved error handling and logging in the GX thread to capture exceptions during command execution.

android/app/src/main/res/values/strings.xml

@@ -188,6 +188,8 @@
     <string name="graphics_bloom_helper">Bloom\'s bright glow reads poorly in a headset, so it starts off.</string>
     <string name="graphics_skip_unready">Prevent shader stutters</string>
     <string name="graphics_skip_unready_helper">Skips a draw for a moment while its shader compiles instead of pausing the game.</string>
+    <string name="graphics_gx_thread">Graphics thread</string>
+    <string name="graphics_gx_thread_helper">Prepares the drawing on a second CPU core so busy scenes keep their speed. Turn off only to compare against the single-threaded path. Takes effect on the next launch.</string>
 
     <!-- Controls tab -->
     <string name="section_controls">Controllers</string>