Openepd

Feat

- **bundle**: add bundle writer
- **bundle**: add bundle models and bundle reader

Fix

- update dependencies

Fix

- change `Impacts` class definition to resolve deserialization issue

Feat

- add `hq_location` to Org, remove `contacts` from Org
- add `epd_developer_email` field
- add `third_party_verifier_email` field
- add location related objects
- add `epd_developer` field
- add `to_serializable` method to the base model
- relax validation

Fix

- fix `get_typed_ext_field` behavior to handle missing data properly

Feat

- add base class for openEPD extensions

Feat

- add convenience method for reading typed objects from ext

Fix

- fix impacts structure