Added
* Added `pydantic` as requirement.
* Added `compas_session.settings.Settings` based on `pydantic.BaseModel`.
* Added `compas_session.session.Session.scene` as default scene.
* Added `compas_session.session.Session.settings` as default settings.
Changed
* Changed `compas_session.namedsession.NamedSession` to `compas_session.session.Session`.
* Changed serialisation dict of session to `{"data": ..., "scene": ..., "settings": ...}`.
Removed
* Removed `compas.scene.Scene` from `compas_session.session.Session.data`.