Map back from mask to original value

[vmenger]

For some applications, it would be nice to have a mapping back from token/mask (redacted value) to the original text, e.g:

patient [NAAM-1] met tel. nr. [TELEFOONNUMMER-1]

should have a mapping:

{'NAAM-1': 'Jan Jansen', 'TELEFOONNUMMER-1': '0612345678'}

That allows re-identification downstream. This requires some thought, because:

• Annotations are frozen dataclasses, so it's hard to set a value on them (i.e. the mask)
• It's not really straightforward to enforce all docdeid.process.Redactor to add a mask to an annotations. For redactors like the RedactAllText, this does not even make sense.
• The current Deduce redactor does fuzzy matching, so a token potentially maps to multiple original values