Setting of `strip flip` in UT should be done in `UTDetector`

The following discussion from !2240 (merged) should be addressed:

• @graven started a discussion: (+6 comments)

Currently, the UT decoding explicitly modifies the UTSectors, instructing whether or not to 'flip' the strip numbering. This should be removed from the decoding, and moved into the UTDetector code instead, and be driven by the content of the conditions database.