Add support for camera frame OSD element

[etracer65]

Recording this so we don't forget to add support for betaflight/betaflight#9261

Needs to be a little more than a simple element. The preview will have to take into account the width/height that are supplied separately in the MSP_OSD_CONFIG message so that the "frame" can be rendered properly. Ideally we should also let the user modify the width/height and these are supplied back the flight controller in MSP_SET_OSD_CONFIG.

My ideal scenario is to add "resize handles" to the corners and let the user drag and resize the camera frame. This would then update the position and width/height as appropriate.

This is potentially an issue with large elements wrapping in the preview that may still need to be addressed from this incomplete PR: #1324

[stale]

This issue / pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs within a week.

[asizon]

Can be closed by #1879

[asizon]

True @mikeller, we still need to enable frame resizing

[haslinghuis]

Fixed in #1879

[haslinghuis]

My ideal scenario is to add "resize handles" to the corners and let the user drag and resize the camera frame. This would then update the position and width/height as appropriate.

Reopening to add a mechanism for

The normal OSD element position is used for the top-left of the frame. New parameters are available for the width/height.

osd_camera_frame_width
osd_camera_frame_height

The width/height are added to the MSP_SET_CONFIG and MSP_SET_OSD_CONFIG MSP messages to support configuring the frame size in the Configurator.