feature(crypto): verification violation handling and block sending

[BillCarsonFr]

Draft as it depends on matrix-org/matrix-rust-sdk#4478

Android part of element-hq/element-meta#2492 (still partial as there is no way to verify other users yet on EX, so you can only withdraw the verification requirement).

Content

When a previously verified user is not anymore there will now be a banner on top of the composer. The composer will be in a disabled state, as anyhow sending will fail (as per element-hq/element-meta#2488)

Motivation and context

Screenshots / GIFs

Dark:

Tests

• Step 1
• Step 2
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Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes have been tested on an Android device or Android emulator with API 24
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request title will be used in the release note, it clearly define what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• You've made a self review of your PR

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