* Improved performance of auth checks (especially `has_field_access()`).
* Changed method signature of `UserScopes.has_all_scopes()` and `UserScopes.has_any_scopes()`
(most callers should use `has_field_access()` anyway.)
* Block `deepcopy()` of schema fields, as it's very slow.
* Removed `DatasetType` base class.
* Removed `schema import events` code, as its no longer used.
* Removed deprecated API's (`schematools.utils` and `is_relation_temporal`).
* Removed wirerope dependency.
* Removed Python 3.8 style annotations.