FeatureRequest: Promote Camera._DisplayPanel to readonly property

[ScruffR]

I came across some cases where I wanted to tie the camera to different display panels depending on the particular QR code I'd wanted to scan.
The QR parsing and other business logic would be the same but had some differences (mostly) revolving around the display.
Although I could have a "global" variable for that but that would add some redundancy and possible cause for error when the two don't always align.
Hence it would be nice to just "ask" the Camera object to which display panel it currently is tied and use that without reason for doubt.

(doing the same for Moniker and FrameSize wouldn't be bad either 😉)