This PR adds logic in categorizeInputs to attempt categorizing unknown input fields to username, based on already categorized password (and other) input fields.

PS: Creates mis-categorisation in chase_2fa-verification-step.html, where there is a one time passcode field, which is very similar semantically to a username field. I haven't figured out a way to filter that case out. Given that we don't really break that site, and still fix two new forms (dplinfo.ssb-ag.de and secure.bankofamerica.com), I'd consider this a win.