AutoTagger: Highlight information about protected files

[thrinn]

When the AutoTagger is called on a selection containing protected files, the protected files will be skipped (at least if "Protected files visible" is not set).  This situation is already indicated on the home page of the AutoTagger. But it is easily overlooked.

I propose to make the protected file count more prominent, e.g. by using a background in a warning color. I also think it would be helpful to repeat this information on the "Lookup and Review Files Manually" page because thumbnails for protected files are not displayed.

[Mario]

Done for IMatch 2023.1.16.