rewrite threads with Kotlin & coroutines (#2617)

* initial class setup

* handle events and filters

* handle status state changes

* code formatting

* fix status filtering

* cleanup code a bit

* implement removeAllByAccountId

* move toolbar into fragment, implement menu

* error and load state handling

* fix pull to refresh

* implement reveal button

* use requireContext() instead of context!!

* jump to detailed status

* add ViewThreadViewModelTest

* fix ktlint

* small code improvements (thx charlag)

* add testcase for toggleRevealButton

* add more state change testcases to ViewThreadViewModel

app/src/main/java/com/keylesspalace/tusky/network/MastodonApi.kt

@@ -167,10 +167,15 @@ interface MastodonApi {
         @Path("id") statusId: String
     ): Single<Status>
 
-    @GET("api/v1/statuses/{id}/context")
-    fun statusContext(
+    @GET("api/v1/statuses/{id}")
+    suspend fun statusAsync(
         @Path("id") statusId: String
-    ): Single<StatusContext>
+    ): NetworkResult<Status>
+
+    @GET("api/v1/statuses/{id}/context")
+    suspend fun statusContext(
+        @Path("id") statusId: String
+    ): NetworkResult<StatusContext>
 
     @GET("api/v1/statuses/{id}/reblogged_by")
     fun statusRebloggedBy(