Fixed bug #45879: Unset menu items for ReaulURL management
[FEATURE] Add hook to post process auto-generated configuration

Add a hook to post process auto-generated configuration.
This allows individual processing for e.g.
* determine default language in multi-tree websites
* define language handling per domain name
* individual additions

Change-Id: I379399e2aa2ae77fcc6babfdae9bf870f0d5a28d
Resolves: #52515