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>

libraries/preferences/impl/src/main/kotlin/io/element/android/libraries/preferences/impl/store/DefaultSessionPreferencesStore.kt

@@ -49,6 +49,7 @@ class DefaultSessionPreferencesStore(
     private val renderReadReceiptsKey = booleanPreferencesKey("renderReadReceipts")
     private val sendTypingNotificationsKey = booleanPreferencesKey("sendTypingNotifications")
     private val renderTypingNotificationsKey = booleanPreferencesKey("renderTypingNotifications")
+    private val skipSessionVerification = booleanPreferencesKey("skipSessionVerification")
 
     private val dataStoreFile = storeFile(context, sessionId)
     private val store = PreferenceDataStoreFactory.create(
@@ -86,6 +87,9 @@ class DefaultSessionPreferencesStore(
     override suspend fun setRenderTypingNotifications(enabled: Boolean) = update(renderTypingNotificationsKey, enabled)
     override fun isRenderTypingNotificationsEnabled(): Flow<Boolean> = get(renderTypingNotificationsKey) { true }
 
+    override suspend fun setSkipSessionVerification(skip: Boolean) = update(skipSessionVerification, skip)
+    override fun isSessionVerificationSkipped(): Flow<Boolean> = get(skipSessionVerification) { false }
+
     override suspend fun clear() {
         dataStoreFile.safeDelete()
     }