DID url pattern does not support accented letters

[SimonVeldhuijzen]

Issue

The DID url pattern does not support accented letters.

As an example, this did:

did:x509:0:sha512:5wgNnRqi2EB4cIg4as6OQfIw_BTy7IGyTyWbTxLyiu7ngNOVCjICCK3q_ZpakaWrNWCtAC9ZAzesmrIT51KcdA::san:otherName:2.16.528.1.1007.99.2110-1-900029306-S-90000380-00.000-11223344::subject:O:Tést%20Zorginstelling%2001::subject:L:%27S-GRAVENHAGE

does not match because of the é character.

Context

This breaks the uzi-did-x509-issuer.

Possible solution

Proposal: add support for accented letters by adjusting the [a-zA-Z0-9.\-_:] part of the regex to [a-zA-Zà-žÀ-Ž0-9.\-_:] or, if supported, [\p{L}0-9.\-_:]

[reinkrul]

Moving to uzi-did-x509-issuer, since the problem lies there. The DID specification doesn't allow accented characters in the DID, so they need to be percent-encoded. There was an attempt to fix this (#34), but this only fixes it for non-letters. I'll get a PR out that adds support for accented letters as well.