[MERGE][FIX] mail: several fixes in discuss, chat window, chatter

This merge fixes a crash in discuss, in addition to re-introduce some _quality of life_
features that have been mistakenly removed from the chatter and from chat windows:

### 1. No crash when searching messages

This was caused by the addition of moderated channels. In short, fetching twice
the same message was performing a re-render of the thread due to a mis-consideration
of a moderation status change. When the fetch reaches the fetch limit, the re-render is
considered as a "load more" fetch, which only works when there is at least one message
registered for the current search.

This is fixed by re-render when there is a change of moderation status only.

Task-ID 1910180

### 2. Easily mention followers and employees in chatter

When mentioning a user from the chatter in a document, it was always
fetching all partners in a arbitrary order. As a result, it was hard to mention
followers and employees.

This is fixed by re-introducing the previous behaviour on mentions, which
groups them by followers, then employees, then all partners.

Task-ID 1910111

### 3. Show message document link in chat window

When a message is linked to a document, it usually shows a
link next to the message. This still works in the Discuss app,
but not in chat windows.

This erroneous regression was caused by a refactoring.
This is fixed by re-introduced document links on messages in chat
windows.

Task-ID 1910119

closes odoo/odoo#28744

1 files changed, 3 insertions, 3 deletions

diff --git a/addons/mail/static/src/js/services/mail_manager.js b/addons/mail/static/src/js/services/mail_manager.js
index 734f12f0cf3..c21089b7095 100644
--- a/addons/mail/static/src/js/services/mail_manager.js
+++ b/addons/mail/static/src/js/services/mail_manager.js
@@ -199,7 +199,7 @@ var MailManager =  AbstractService.extend({
      * Get partners as mentions from a chatter
      * Typically all employees as partner suggestions.
      *
-     * @returns {Array<Object[]>}
+     * @returns {Array<Array<Object[]>>}
      */
     getMentionPartnerSuggestions: function () {
         return this._mentionPartnerSuggestions;
@@ -1195,8 +1195,8 @@ var MailManager =  AbstractService.extend({
      *
      * @private
      * @param {Object} result data from server on mail/init_messaging rpc
-     * @param {Object[]} result.mention_partner_suggestions list of suggestions
-     *   with all the employees
+     * @param {Array<Object[]>} result.mention_partner_suggestions list of
+     *   suggestions.
      * @param {integer} result.menu_id the menu ID of discuss app
      */
     _updateInternalStateFromServer: function (result) {