Implement redraft feature. (#1190)

* Implement "Delete and Edit" feature

* Some changes to ComposeActivity

Support for uploaded medias, sensitive option.

Fix typo.

Change names of some extra keys.

* Use Glide instead of Picasso

* Pass ArrayList instead of json

* Change wording for re-draft

* Fix test

app/src/main/java/com/keylesspalace/tusky/components/conversation/ConversationEntity.kt

@@ -71,7 +71,7 @@ data class ConversationStatusEntity(
         val favourited: Boolean,
         val sensitive: Boolean,
         val spoilerText: String,
-        val attachments: List<Attachment>,
+        val attachments: ArrayList<Attachment>,
         val mentions: Array<Status.Mention>,
         val showingHiddenContent: Boolean,
         val expanded: Boolean,