feat(outbound): add voice announcement on trunk congestion & clarify MoH options

src/Database.php

@@ -639,7 +639,7 @@ class Database
                 ':agroups'      => json_encode($grps),
                 ':aexts'        => json_encode($exts),
                 ':cont'         => 1,
-                ':cdest'        => 'terminate-busy',
+                ':cdest'        => 'all-circuits-busy',
                 ':rec'          => 'dontcare',
             ]);