Add TOS notice on account activation

[Geri680]

Fix #2070

Something like Addy.io done:

[Geri680]

@nguyenkims please take a look

[nguyenkims]

Thanks for the idea. The UI is a bit not polished enough though, if you want we can ask our designers

[Geri680]

@nguyenkims, I think this will be good :)

We need to inform users shortly because not everyone will read full ToS

[Geri680]

@nguyenkims maybe it is even better to make something like that:

User press “Sign up” -> Page with this short ToS -> User accepts it -> https://app.simplelogin.io/auth/register opens

I think this will be best way to add this. Don’t you think so?