The goal of this issue is to have the ability to force all new "team members" (users who are notified they got a new account created) to accept the Terms and conditions of the Matomo.

For example as part of GDPR compliance, it may be that an agency needs to enforce their customers respect their data protection agreement and/or terms of service.

Proposed steps:

• Let Super Users define a "Terms and Conditions" page in General settings
• When the page is defined, then any new user receiving a new account, when they try and change their password, will have to also agree to the terms and conditions by checking the box. The wording could say [ ] By using this service, I hereby accept the [Terms and conditions](links).
• Existing users wouldn't have to agree to the terms (only apply to new users)
• In the Administration UI, we should display a link to the Terms and conditions. For example the System Summary widget could be a good place for it, maybe like this?