MM-44568: sanitizes profiles in posts (#20291)

* MM-44568: sanitizes profiles in posts

* Fixes tests

* Adds test

* Satisfy vet

store/sqlstore/post_store.go

@@ -1071,6 +1071,7 @@ func (s *SqlPostStore) prepareThreadedResponse(posts []*postWithExtra, extended,
 			return nil, err
 		}
 		for _, user := range users {
+			user.SanitizeProfile(map[string]bool{})
 			usersMap[user.Id] = user
 		}
 	} else {