MDL-79397 reportbuilder: update reports to use auto-generated aliases.

We no longer need to be concerned about the manual setting of entity
table aliases (e.g. to avoid duplication between entities, or for using
a single entity multiple times), as it's handled transparently for us.

notes/classes/reportbuilder/datasource/notes.php

@@ -68,17 +68,14 @@ class notes extends datasource {
                    ON {$recipientalias}.id = {$postalias}.userid")
         );
 
-        // Join the user entity to represent the note author. Override all entity table aliases to avoid clash with first instance.
+        // Join the user entity to represent the note author.
         $authorentity = (new user())
             ->set_entity_name('author')
-            ->set_entity_title(new lang_string('author', 'core_notes'))
-            ->set_table_aliases([
-                'user' => 'au',
-                'context' => 'auctx',
-            ]);
+            ->set_entity_title(new lang_string('author', 'core_notes'));
+        $authoralias = $authorentity->get_table_alias('user');
         $this->add_entity($authorentity->add_join("
-            LEFT JOIN {user} au
-                   ON au.id = {$postalias}.usermodified")
+            LEFT JOIN {user} {$authoralias}
+                   ON {$authoralias}.id = {$postalias}.usermodified")
         );
 
         // Join the course entity for course notes.