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/entity/Status.kt

@@ -36,7 +36,7 @@ data class Status(
         var sensitive: Boolean,
         @SerializedName("spoiler_text") val spoilerText: String,
         val visibility: Visibility,
-        @SerializedName("media_attachments") var attachments: List<Attachment>,
+        @SerializedName("media_attachments") var attachments: ArrayList<Attachment>,
         val mentions: Array<Mention>,
         val application: Application?,
         var pinned: Boolean?