User Upgrade Criteria

[Foxtrek_64]

Please add a User Criteria tab to User Upgrades. This will allow us to limit the ability to purchase upgrades to those who are members of certain user groups or who have 2FA enabled or any other criteria selected by an admin.

Also, there should be some sort of option added in the options page for how to display unavailable upgrades. My thinking is a radio set:

• Do not display unavailable upgrades.
• Show unavailable upgrades with disabled purchase button.

An option per-upgrade should be added to display the missing criteria should the purchase not be available. This can be useful when the criteria is not a security risk to reveal. For instance, in a game server, a user upgrade may only be available to those who have been whitelisted on the server (where it'd be a moot point for those not whitelisted to purchase the upgrades).