Init color calibration box on the current bounding box.

[TurboGit]

This make it possible to zoom on the part of the image where the color checker is and have the handle for the calibration chart on screen be visible.

[TurboGit]

Take the mire.cr2 from the integration test:

Zoom on the chart and expand the calibrate collapsible section of color calibration:

The handles for aligning the chart are positioned based on the full image:

Not really useful to align the chart on a small area of the picture, now after the zoom is done when we expand the calibrate collapsible section of color calibration:

So that's a small usability enhancement, something that was itching me since some time.