Hide encryption history + FTUE flow (#839)

* First attempt at implementing encrypted history banner and removing old UTDs

* Get the right behavior in the timeline

* Implement the designs

* Extract post-processing logic, add tests

* Add encryption banner to timeline screenshots

* Create FTUE feature to handle welcome screen and analytics

* Move classes to their own packages, add tests for `DefaultFtueState`.

* Remove unnecessary private MutableStateFlow

* Move some FTUE related methods and classes back to the `impl` module

* Handle back press at each FTUE step

* Remove unneeded `TestScope` receiver for `createState` in tests.

* Use light & dark previews for the banner view.

* Move color customization from `TextStyle` to `Text` component.

* Rename `InfoList` design components, use them in `AnalyticsOptInView` too.

* Cleanup MatrixClient.

* Fix copy&paste error

Co-authored-by: Benoit Marty <benoit@matrix.org>

* Fix typo

* Fix Maestro tests

---------

Co-authored-by: ElementBot <benoitm+elementbot@element.io>
Co-authored-by: Benoit Marty <benoit@matrix.org>

.maestro/tests/assertions/assertWelcomeScreenDisplayed.yaml

@@ -0,0 +1,6 @@
+appId: ${APP_ID}
+---
+- extendedWaitUntil:
+    visible:
+      id: "welcome_screen-title"
+    timeout: 10_000