Template annotation: textual inputs

[xtrojak]

The textual inputs (variable name corresponding to a ROI, expected value in a residual, path to a dictionary of allowed values, ...) can be handled from command line, but it's not very robust requires changing context between the image and command line). This should be improved.

[xtrojak]

Another way around this is to assing just integer IDs to individual regions and then assign them variable names e.g. via a mapping from text file.