Fix a few FFI leaks (#405)

Fix a few FFI leaks

These are instances where we obtain an FFIObject and don't call
Close on it to release the underlying reference on the Rust side.

The worst instance here was leaking an object per room member
every time we refreshed the member list

samples/minimal/src/main/kotlin/io/element/android/samples/minimal/RoomListScreen.kt

@@ -33,17 +33,16 @@ import io.element.android.libraries.dateformatter.impl.LocalDateTimeProvider
 import io.element.android.libraries.designsystem.utils.SnackbarDispatcher
 import io.element.android.libraries.matrix.api.MatrixClient
 import io.element.android.libraries.matrix.api.core.RoomId
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.asCoroutineDispatcher
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import kotlinx.datetime.Clock
 import kotlinx.datetime.TimeZone
 import java.util.Locale
-import java.util.concurrent.Executors
 
 class RoomListScreen(
     context: Context,
     private val matrixClient: MatrixClient,
+    private val coroutineDispatchers: CoroutineDispatchers = Singleton.coroutineDispatchers,
 ) {
     private val clock = Clock.System
     private val locale = Locale.getDefault()
@@ -58,28 +57,24 @@ class RoomListScreen(
         sessionVerificationService = sessionVerificationService,
         networkMonitor = NetworkMonitorImpl(context),
         snackbarDispatcher = SnackbarDispatcher(),
-        inviteStateDataSource = DefaultInviteStateDataSource(
-            matrixClient,
-            DefaultSeenInvitesStore(context),
-            CoroutineDispatchers(
-                io = Dispatchers.IO,
-                computation = Dispatchers.Default,
-                main = Dispatchers.Main,
-                diffUpdateDispatcher = Executors.newSingleThreadExecutor().asCoroutineDispatcher()
-            )
-        )
+        inviteStateDataSource = DefaultInviteStateDataSource(matrixClient, DefaultSeenInvitesStore(context), coroutineDispatchers)
     )
 
     @Composable
     fun Content(modifier: Modifier = Modifier) {
         fun onRoomClicked(roomId: RoomId) {
-            val room = matrixClient.getRoom(roomId)!!
-            val timeline = room.timeline()
             Singleton.appScope.launch {
-                timeline.apply {
-                    initialize()
-                    paginateBackwards(20, 50)
-                    dispose()
+                withContext(coroutineDispatchers.io) {
+                    matrixClient.getRoom(roomId)!!.use { room ->
+                        val timeline = room.timeline()
+
+                        timeline.apply {
+                            // TODO This doesn't work reliably as initialize is asynchronous, and the timeline can't be used until it's finished
+                            initialize()
+                            paginateBackwards(20, 50)
+                            dispose()
+                        }
+                    }
                 }
             }
         }