[Devices Management] Header view for sessions lists in new layout (PSG-668)

[mnaturel]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

Adding a nex custom view for headers which will be used in sessions lists in the new layout.

Motivation and context

See #6806

Screenshots / GIFs

Tests

• Enable the new device management feature flag
• Go to "Security & Privacy" settings
• Press the "Show all sessions (V2, WIP)" entry
• Check the header for "Other sessions" section is visible
• Press "Learn more"
• Check there is a toast displayed

Tested devices

• Physical
• Emulator
• OS version(s): Android 11

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/vector-im/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/vector-im/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()

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[onurays]

LGTM! Just added minor commits.