fix: normalize usernames with NFC to dedupe umlaut variants

[JanKru]

Checklist for PR

• PR is only about one and only one concern
• Description contains a short title, an optional description, and the sections BEFORE and AFTER
• (A) new short test(s) show(s) that the PR is working

Some more infos

In calcTeamAlignment, the actualTeams set can end up containing "duplicate" entries for the same user when their name includes an umlaut. This happens because JavaScript strings with precomposed (“ä” U+00E4) and decomposed (“a\u0308” + COMBINING DIAERESIS) representations are treated as distinct values by Set. We need to normalize all usernames to NFC before using them as keys so that “Mäster” and “Mäster” collapse to the same string.

BEFORE:
You will end up with two users in the set

AFTER:
Only one user. Test in team-alignment.spec.tsshould clearify

[wolfmanfx]

Hi, I think I added a merge by email adress so this should not an issuse anymore when my PR is merged.

[JanKru]

Hi Murat,
Not an expert on the field but since RFC 6531 (SMTPUTF8, Internationalized Email). Some E-Mails could in theory contain Umlauts?

Thx for reply

Jan