Fix regular expressions containing redundant prefix and update local identifier validation

[cthoyt]

Closes #191

This PR does two things:

1. It uses the "cleaned identifiers" (which will hopefully get a better name later) for regex checking. This means that rather than adding a redundant namespace in LUI before doing the regex check, it explicitly removes them
2. Update regex patterns that include namespace in LUI to no longer include the namespace. Keep in mind these are only written this way likely because of a deep confusion between local unique identifiers and CURIEs held by the MIRIAM database curators almost 10 years ago that has never been fixed. See Confused about how Namespace in Pattern works #191 (comment) for a more thorough explanation.

This PR will not be merged until there is a consensus on this. I will bring it up in discussion at the Fall 2021 Workshop on Prefixes, CURIEs, and IRIs which is on October 29th, then give everyone about a week to give feedback.

See also #214 where the web UI is updated to better convey the difference between a regular expression pattern that's for a local identifier versus for a compact URI (i.e., CURIE), which must, by definition, contain the prefix.