Implement ULID.parse()

[perrotuerto]

The package ulid-py has the classmethod parse, used when the caller is trying to parse a ULID from a value when they're unsure what format/primitive type it will be given in.

This PR implements ULID.parse() for this package and according to its API.

[dhavalsavalia]

Thanks! Just when I was about to write this myself.

Thank you so much once again!

[perrotuerto]

Hi, any feedback about this PR?

[mdomke]

@perrotuerto Thank you very much and sorry for the veeery long response time