Timeline refactor (#2175)

* Move Timeline files into their own package

* Introduce TimelineViewModel, add coroutines

* Simplify StatusViewData

* Handle timeilne fetch errors

* Rework filters, fix ViewThreadFragment

* Fix NotificationsFragment

* Simplify Notifications and Thread, handle pin

* Redo loading in TimelineViewModel

* Improve error handling in TimelineViewModel

* Rewrite actions in TimelineViewModel

* Apply feedback after timeline factoring review

* Handle initial failure in timeline correctly

app/src/test/java/com/keylesspalace/tusky/BottomSheetActivityTest.kt

@@ -91,7 +91,7 @@ class BottomSheetActivityTest {
             "",
             Status.Visibility.PUBLIC,
             ArrayList(),
-            arrayOf(),
+            listOf(),
             null,
             pinned = false,
             muted = false,