Apphelpers

-------------------
* Added response_model for FastAPI endpoints

-------------------
* Fixed operation_id generation

-------------------
* Fixed _get_matched_keys access for ReadOnlyCachedModel

-------------------
* site_ctx implementation for FastAPI
* user_agent directive for FastAPI & Hug
* ignore_site_ctx implementation for FastAPI & Hug
* count_matched_keys implementation for ReadOnlyCachedModel

-------------------
* Breaking: moved apphelpers.sessions.whoami to apphelpers.rest.{hug/fastapi}.whoami
* New convenient decorators in apphelpers.rest.endpoint
* any_group_required and all_groups_required implementation for FastAPI
* Improved errors
* Other improvements and fixes
* Moved CI from travis to github actions

-------------------
* Support for FastAPI framework.