Create SyncOrchestrator (#4176)

* Create `SyncOrchestrator` to centralise the sync start/stop flow through the whole app: the decision is based on several inputs: sync state, network available, app in foreground, app in call, app needing to sync an event for a notification.

* Make network monitor return network connectivity status, not internet connectivity

* Don't stop the `SyncService` when network connection is lost, let it fail instead. This prevents an issue when using the offline mode of the SDK, which made the wrong UI states to be shown when the `SyncState` is `Idle` (that is, after the service being manually stopped).

* Rename `NetworkStatus.Online/Offline` to `Connected/Disconnected` so they're not easily mistaken with internet connectivity instead

services/appnavstate/api/src/main/kotlin/io/element/android/services/appnavstate/api/AppForegroundStateService.kt

@@ -18,8 +18,28 @@ interface AppForegroundStateService {
      */
     val isInForeground: StateFlow<Boolean>
 
+    /**
+     * Updates to whether the app is in an active call or not will be emitted here.
+     */
+    val isInCall: StateFlow<Boolean>
+
+    /**
+     * Updates to whether the app is syncing a notification event or not will be emitted here.
+     */
+    val isSyncingNotificationEvent: StateFlow<Boolean>
+
     /**
      * Start observing the foreground state.
      */
-    fun start()
+    fun startObservingForeground()
+
+    /**
+     * Update the in-call state.
+     */
+    fun updateIsInCallState(isInCall: Boolean)
+
+    /**
+     * Update the active state for the syncing notification event flow.
+     */
+    fun updateIsSyncingNotificationEvent(isSyncingNotificationEvent: Boolean)
 }