Remove SessionData.needsVerification as the source of truth for session verification status (#2748)

* Remove `SessionData.needsVerification` as the source of truth for session verification status.

- Use the Rust SDK `EncryptionService.verificationState()` instead, but always waiting for the first 'known' result (either verified or not, discarding 'unknown').
- Add a workaround in the super rare case when reading this value gets stuck somehow. We'll assume the user is not verified in that case.
- Make `DefaultFtueService.getNextStep` and dependent checks `suspend`.
- Make the `skip` button use a value in the session preferences instead.

* Log exception when the verification status can't be loaded

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

* Fix review comments

---------

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

features/verifysession/impl/build.gradle.kts

@@ -42,6 +42,7 @@ dependencies {
     implementation(projects.libraries.matrix.api)
     implementation(projects.libraries.matrixui)
     implementation(projects.libraries.designsystem)
+    implementation(projects.libraries.preferences.api)
     implementation(projects.libraries.uiStrings)
     api(libs.statemachine)
     api(projects.features.verifysession.api)
@@ -53,6 +54,7 @@ dependencies {
     testImplementation(libs.test.truth)
     testImplementation(libs.test.turbine)
     testImplementation(projects.libraries.matrix.test)
+    testImplementation(projects.libraries.preferences.test)
     testImplementation(projects.tests.testutils)
     testImplementation(libs.androidx.compose.ui.test.junit)
     testReleaseImplementation(libs.androidx.compose.ui.test.manifest)