Rename bcp47 to lang #1139
Description
Summary
IETF Bcp47 is a standard defining a type. It's not an attribute. We should name attributes describing language with what they describe, not their type, and validate type accordingly.
All probes, generators, detectors and others with an attribute of "bcp47" should rename that attribute "lang" and validate its content by bcp47, while also allowing "*". Allowing nonetype is context specific.