Add a Stuck Value test for position

[squaregoldfish]

From Michael Glockzin:

Position QC is good to do, I just recognized that QuinCe does not flag
"double" GPS LAT and LON data in a row, eg if the GPS is down (then it
repeats the same values over and over again in our system), thats hard
to see in the plots, but in the tables.

Do we add an option so users can choose if they want a "Stuck Value" GPS test?