[MM-27535] User invite limits for MM Cloud (#15197)

* Add a config for MM User Limit

* Adding graceful errors for if an administrator invites people passed their user limit

* Including changed vendor files

* Adding unit test

* Fix a bug

* Push up working tests (Thanks Joram)

* Add more cases, clean up logs in code

* One more case

* Refactoring based on PR comments

* Updating i18n

* Some changes based on PR review

* Remove a comment

* Bring back some translations that were somehow removed

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

i18n/en.json

@@ -2214,6 +2214,10 @@
     "id": "api.team.invite_members.invalid_email.app_error",
     "translation": "The following email addresses do not belong to an accepted domain: {{.Addresses}}. Please contact your System Administrator for details."
   },
+  {
+    "id": "api.team.invite_members.limit_reached.app_error",
+    "translation": "You've reached the user limit of your current tier"
+  },
   {
     "id": "api.team.invite_members.no_one.app_error",
     "translation": "No one to invite."