Is your feature request related to a problem? Please describe.
In the datastreams version of subjects (inveniosoftware/invenio-vocabularies#322) several identifier schemes should be supported, e.g. gnd, lcsh, rameau and more.
Describe the solution you'd like
Implement is_lcsh, is_rmeau, normalize_lcsh, normalize_rameau.
Describe alternatives you've considered
None.
Additional context
The rameau identifier is an ark implementation (e.g. https://data.bnf.fr/ark:/12148/cb16656930x). It might be sufficient to just check if an id is an ark. So it might be a good idea to first fix #79