minor
Quickly drop tables
Implemented a materialized view (without the corresponding triggers yet) for `Node.name_path` as a table `NodeEx` which is linked to `Node` via a foreign link `NodeEx.node_id` and *also* inherits from `Node` on the SQLAlchemy level. The foreign key is probably the correct way to go, but I'm not so sure about inheriting from `Node` and calling the materialized view `NodeEx` on the Python side: Maybe `NodePath` (with properties like e.g. `id_path`, `uuid_path`, `name_path`) would actually be cleaner. Investigate and fix!
DbDrop need to be fixed!