### 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.
BitField<OpenXRInterface::HandJointFlags> bits;
	OpenXRHandTrackingExtension *hand_tracking_ext = OpenXRHandTrackingExtension::get_singleton();
	if (hand_tracking_ext && hand_tracking_ext->get_active()) {
		XrSpaceLocationFlags location_flags = hand_tracking_ext->get_hand_joint_location_flags(OpenXRHandTrackingExtension::HandTrackedHands(p_hand), XrHandJointEXT(p_joint));
		if (location_flags & XR_SPACE_LOCATION_ORIENTATION_VALID_BIT) {
			bits.set_flag(HAND_JOINT_ORIENTATION_VALID);
		}
		if (location_flags & XR_SPACE_LOCATION_ORIENTATION_TRACKED_BIT) {
			bits.set_flag(HAND_JOINT_ORIENTATION_TRACKED);
		}
		if (location_flags & XR_SPACE_LOCATION_POSITION_VALID_BIT) {
			bits.set_flag(HAND_JOINT_POSITION_VALID);
		}
		if (location_flags & XR_SPACE_LOCATION_POSITION_TRACKED_BIT) {
			bits.set_flag(HAND_JOINT_POSITION_TRACKED);
		}
		XrSpaceVelocityFlags velocity_flags = hand_tracking_ext->get_hand_joint_velocity_flags(OpenXRHandTrackingExtension::HandTrackedHands(p_hand), XrHandJointEXT(p_joint));
		if (velocity_flags & XR_SPACE_VELOCITY_LINEAR_VALID_BIT) {
			bits.set_flag(HAND_JOINT_LINEAR_VELOCITY_VALID);
		}
		if (velocity_flags & XR_SPACE_VELOCITY_ANGULAR_VALID_BIT) {
			bits.set_flag(HAND_JOINT_ANGULAR_VELOCITY_VALID);
		}
	}
	return bits;
}
Quaternion OpenXRInterface::get_hand_joint_rotation(Hand p_hand, HandJoints p_joint) const {