Add language dropdown to compose view (#2651)

* Add UI for selecting post language

* Apply selected language when sending status

* Save/restore post language with drafts

* Fall back to english if the configured language isn't found in the locale list (no-NB)

* Remove comment about no_NB

* Move language dropdown to top of compose view

* Preserve language when redrafting

* Set default language to target post's language when replying

* Add Tusky license header to new source file

* Tweak language dropdown button width

app/src/main/java/com/keylesspalace/tusky/entity/DeletedStatus.kt

@@ -27,7 +27,8 @@ data class DeletedStatus(
     val sensitive: Boolean,
     @SerializedName("media_attachments") var attachments: ArrayList<Attachment>?,
     val poll: Poll?,
-    @SerializedName("created_at") val createdAt: Date
+    @SerializedName("created_at") val createdAt: Date,
+    val language: String?,
 ) {
     fun isEmpty(): Boolean {
         return text == null && attachments == null