FEATURE: Publish read state on group messages. (#7989) [Undo revert] (#8024)

* Reenable: "FEATURE: Publish read state on group messages. (#7989)"

This reverts commit 67f5cc1ce8.

* FIX: Read indicator only appears when the group setting is enabled

config/locales/client.en.yml

@@ -2421,6 +2421,7 @@ en:
         reply: "begin composing a reply to this post"
         like: "like this post"
         has_liked: "you've liked this post"
+        read_indicator: "members who read this post"
         undo_like: "undo like"
         edit: "edit this post"
         edit_action: "Edit"
@@ -2478,6 +2479,7 @@ en:
           notify_user: "sent a message"
           bookmark: "bookmarked this"
           like: "liked this"
+          read: "read this"
           like_capped:
             one: "and {{count}} other liked this"
             other: "and {{count}} others liked this"
@@ -3217,6 +3219,7 @@ en:
             members_visibility_levels:
               title: "Who can see this group members?"
               description: "Admins can see members of all groups."
+            publish_read_state: "On group messages publish group read state"
 
           membership:
             automatic: Automatic

config/routes.rb

@@ -614,6 +614,7 @@ Discourse::Application.routes.draw do
   get "excerpt" => "excerpt#show"
 
   resources :post_action_users
+  resources :post_readers, only: %i[index]
   resources :post_actions do
     collection do
       get "users"

config/site_settings.yml

@@ -191,9 +191,10 @@ basic:
   post_menu:
     client: true
     type: list
-    default: "like|share|flag|edit|bookmark|delete|admin|reply"
+    default: "read|like|share|flag|edit|bookmark|delete|admin|reply"
     allow_any: false
     choices:
+      - read
       - like
       - edit
       - flag