[ocis] Autoprovisioning: Update users when attributes change

[rhafer]

When autoprovisioning is enabled and one of the claim values changed ((e.g. the displayname or mail address) since the initial user creation we don't update the local user account. We should implement that.

(Note: this is specifically not about user's being renamed.)

[rhafer]

@micbar @tbsbdr I think this relevant to mature the autoprovsioning feature