Add a non-dismissable verification banner

[bmarty]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

Add a non-dismissable verification banner on the room list.

Motivation and context

Closes #9121
Part of element-hq/element-meta#2833

Screenshots / GIFs

Screen_recording_20260210_141250.mp4

Light	Dark

Tests

• Signin to your account
• Observe the new non-dismissable banner, displayed until the session is verified.

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/element-hq/element-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[jmartinesp]

LGTM!