Optional Account<>IP Binding

Optional feature to let us, static IP users to lock accounts on top of the (before) 2FA feature.
eg No other IP will be able to proceed with the login process, even with correct credentials.
This will also eliminate bruteforce attempts on rare account names and add extra, optional security.

Manual unbinding via email provided hash link, same as password reset - in case of changed IP or other reasons.
No staff interaction required.

2FA feature is pretty flexible and solid, especially for dynamic ip users, but not flawless and for sure not that secure either. Especially ingame, remembering every IP you've ever authenticated with for the world login, also giving you a X minutes window to log on the website, without triggering the 2FA - no IP/UA comparison in that case.