Notify user when data loaded has different pipeline hashes

[paulmueller]

I.e. if you are analyzing two datasets with different dcnum pipeline identifiers, Shape-Out should warn you that you are comparing apples and oranges.

[paulmueller]

It shouldn't be a pop-up window that the user can ignore. It should be e.g. a red text added to the plots. Can be done like for the contour spacing warning in the image:

[paulmueller]

https://github.com/ZELLMECHANIK-DRESDEN/ShapeOut2/pull/219