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/ViewMediaActivity.kt

@@ -47,6 +47,7 @@ import autodispose2.autoDispose
 import com.bumptech.glide.Glide
 import com.bumptech.glide.request.FutureTarget
 import com.keylesspalace.tusky.BuildConfig.APPLICATION_ID
+import com.keylesspalace.tusky.components.viewthread.ViewThreadActivity
 import com.keylesspalace.tusky.databinding.ActivityViewMediaBinding
 import com.keylesspalace.tusky.entity.Attachment
 import com.keylesspalace.tusky.fragment.ViewImageFragment