feat: refactor AccessEntry to use _properties pattern (#1125)

* add view, dataset, routine properties

* add properties and unit tests

* lint

* add properties and tests

* remove unused imports

* update test

* add tests

* add tests

* add tests

* add more tests

* update return type

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* refactor to use get() and remove self._entity_id

* delete unnecessary file

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* add types, remove unnecessary checks

* fix types

* types

* add type casting

* refactor AccessEntry repr

* update to return DatasetReference

* update to use RoutineRef and TableRef

* add table test

* update to use api_repr

* lint

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* Update google/cloud/bigquery/dataset.py

Co-authored-by: Tim Swast <swast@google.com>

* update tests

* remove repeat type import

Co-authored-by: Tim Swast <swast@google.com>