Flint: Display ROI location into the image scan

Feedback from many beamlines (ID10, ID31, ID11).

The image widget should be able to display the location of the ROIs from the current scan.

For now this information is contained in the Redis Lima node info. Which is AFAICR not convenient to use.

It would be good to check it again, or to move/dup it to a proper place (the common scan info).