babl: add bitmask flags for meta-data about models

babl: add bitmask flags for meta-data about models

Refactored from new API needed internally for knowing if a model is CMYK based
or not, this permits adding meta-data that can be quickly figured out in
possible fast code paths. The API is not complete, and it probably doesn't harm
to include as many features from different models as possible that fit in a
bitmask, adding the most important ones first and maintaining the order of the
enum will ensure API compatibility once it is in a release.