use the FAPRGRM keyword rather than PROGRAM when displaying exposure types

[sybenzvi]

Rongpu noticed that BACKUP tiles 41149 and 42743 on 20250122 were labeled as BRIGHT in the exposure list. This is likely due to reading the PROGRAM keyword from the FITS header instead of FAPRGRM.

Update so that we read FAPRGRM with PROGRAM as a default backup.

[sybenzvi]

Note: the FAPRGRM keyword is set properly during assembly of the fibermap file and will need to be added to the QA header from there.