### Godot version

4.2.dev 80de898d721f952dac0b102d48bb73d6b02ee1e8

### System information

OpenXR

### Issue description

The Godot 3 OpenXR plugin supported obtaining boundary/guardian information in order to obtain play space logic. While we do have a function in the `XRInterface` in Godot 4 that is supposed to retrieve this information (`get_play_area`) it is not implemented on the Godot 4 `OpenXRInterface`.

This logic needs to be ported.

### Steps to reproduce

Call `get_play_area`, be amazed by it not returning data :P

### Minimal reproduction project

Any XR project.
case 0: {
				reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
			} break;
			case 1: {
				reference_space = XR_REFERENCE_SPACE_TYPE_STAGE;
			} break;
			default:
				break;
		}
		int environment_blend_mode_setting = GLOBAL_GET("xr/openxr/environment_blend_mode");
		switch (environment_blend_mode_setting) {
			case 0: {
				environment_blend_mode = XR_ENVIRONMENT_BLEND_MODE_OPAQUE;
			} break;
			case 1: {
				environment_blend_mode = XR_ENVIRONMENT_BLEND_MODE_ADDITIVE;
			} break;
			case 2: {
				environment_blend_mode = XR_ENVIRONMENT_BLEND_MODE_ALPHA_BLEND;
			} break;
			default:
				break;
		}
		submit_depth_buffer = GLOBAL_GET("xr/openxr/submit_depth_buffer");
	}
	
	frame_state.predictedDisplayTime = 0;
	frame_state.predictedDisplayPeriod = 0;
}
OpenXRAPI::~OpenXRAPI() {