Invisible Crypto: EX iOS: display a warning when an *unverified* user changes identity

[andybalaam]

Followup to #2492. Part of #2491, itself part of Invisible crypto.

When an unverified user changes their identity, we need to make our user aware of this. In the long term, the intention is just to show a notice in the timeline (#2493); however, that is difficult to implement and we need a stop-gap.

This task is for Element X iOS.

The proposal is to show a warning above the composer, in much the same way as we would for verified users (#2491), but without locking the composer.

Figma designs:

• EXI

[mxandreas]

@stefanceriu I am guessing you're taking care of this for iOS, if not please tag who is.

@bmarty Asked a question what should the Learn more link do. We did a quick iteration with @americanrefugee and landed on the following.

1. The Learn more link will open this help screen - there is an equivalent for Android and Web in Figma.

Samples:

2. The Go to FAQ would then open browser that will lead to https://element.io/help#encryption (final URL TBD - we have the content but still need to publish it).

@andybalaam @richvdh @BillCarsonFr for visibility.

[americanrefugee]

This what I have for Web

[mxandreas]

Updated my comment above to have the complete info.

[stefanceriu]

@mxandreas This is a bit unexpected to be honest. All our 'learn more' kind of links always point to somewhere on the web i.e. https://github.com/element-hq/element-x-ios/blob/e6f4dd33a0326081a03553f3d8f6a21ca3c2041b/ElementX/Sources/Application/AppSettings.swift#L116-L126

Why are we building a custom screen for this one when we can easily send people to a new section on the same https://element.io/help#encryption? (Especially as this is a full screen pushed onto the navigation stack which makes it extra hard to implement)

[mxandreas]

The idea was that it would be more "accessible", but if it increases complexity of the implementation, then it is not worth it, I think. cc @americanrefugee - I am fine this link to go directly to the web and have all the content there. Let me know if you have any further thoughts.

[mxandreas]

The Learn more link should lead to: https://element.io/help#encryption18 - let's skip the in-app screen to save effort for now.

Product marketing did some final touches on the content so that it would fit into the FAQ format. There are a couple of details that we could improve IMO or make it more specific but I did not want to do another iteration and block the work. We can update content on the website independently.

cc @bmarty @uhoreg

[mxandreas]

The correct link is https://element.io/help#encryption18 - fixed it above as well but just in case. Sorry for confusion.