respdiff/cfg: check fields in criteria/field_weights
MR changes two things:
- Fields in config (
criteria/field_weights) are now checked against a supported list, any typos will cause an error. - All fields must be present in
field_weightsnow. This change is backward incompatible and requires updates to existingrespdiff.cfg. I've found the previous default checks a field usingcriteriain msgdiff, but it is never reported in diffsum, since it has no weight assigned. @pspacek Is there any valid reason why a field wouldn't be present infield_weights?