[APP-690] better handling of post languages language filtering (#893)

* add SelectLangBtn

* memoized objects that are created to reduce re-creation on re-render

* add langs when uploading post

* only send the top 3 languages otherwise backend will throw error

* mv ContentLanguagesSettings to folder

* add post languages settings modal and state

* fix typos

* modify feed manip to also check langs label on post

* Fix tests

* Remove log

* Update feed-manip.ts

* Fix syntax errors

* UI tuneups

* Show the currently selected languages in the composer

* fix linting

* Use a bcp-47 matching function

* Fix a duplicate language issue

* Fix web

* Dont include lang in prompt

* Make select language btn an observer

* Keep device languages on top of language selection UIs

* Fix android build settings

* Enforce a max of 3 languages in posts

* Fix tests

* Fix types

---------

Co-authored-by: Paul Frazee <pfrazee@gmail.com>

src/state/models/ui/shell.ts

@@ -111,6 +111,10 @@ export interface ContentLanguagesSettingsModal {
   name: 'content-languages-settings'
 }
 
+export interface PostLanguagesSettingsModal {
+  name: 'post-languages-settings'
+}
+
 export interface PreferencesHomeFeed {
   name: 'preferences-home-feed'
 }
@@ -125,6 +129,7 @@ export type Modal =
   // Curation
   | ContentFilteringSettingsModal
   | ContentLanguagesSettingsModal
+  | PostLanguagesSettingsModal
   | PreferencesHomeFeed
 
   // Moderation