Make IS terms wording clearer when we fallback to vector.im

[manuroe]

When the user has not set an IS yet, the app tries to use vector.im (or any url specified by the HS well-known or the one defined by identityserverurl in the app plist).
The issue is that the app falls back to it without any notice. vector.im terms are displayed to the end user without a clear context. Plus, they can appear from anywhere because of network latency.
This video shows the current confusing UX and the latency issue that makes terms appear a bit out of context

For the moment, we just want to improve the wording of the terms screen as a quick fix.
We should also let the user decide to not use any IS like riot-web does with the "Do not use an identity server" button in the settings in such condition.

The current terms screen (that can appear from nowhere):

[nadonomy]

Would it be possible to poll/check whether a user has granted permission ahead of time, so we can display this modal consent immediately after the user taps on something that requires consent?

[manuroe]

@nadonomy not really. As this request is async, we can get the answer lately.

[manuroe]

@nadonomy what do you think about the following screen?
This variant of the ToS screen will be displayed only in case where the user has not set an IS yet and when they enter in the people tab or when they want to invite people into a room.

[nadonomy]

@manuroe can we use:

• A title of "Contact discovery" to aid context quicker for users scanning/not really reading
• Body text of "Accept the terms of the identity server (https://vector.im) to discover contacts." to exercise brevity
• And "Decline" to exercise brevity again on the last button