To facilitate multiple identifiers of OUs we introduce the OuIdentifier
model and removed the orgreg_id field from OrganizationalUnit.

All current orgreg_ids are recreated as OuIdentifiers with name
'orgreg_id' and source 'orgreg'. Both values are configurable in the
base settings file in the gregsite app. Note that changing this value
after migration will require manual work changing all OuIdentifiers
already created before the next run of the orgreg_import management
command since that assumes all current orgreg identifiers uses these
values.

All endpoints that previously exposed the orgreg_id field now exposes an
identifiers field with a list of OuIdentifiers connected to that model
with fields id, name, source, and value.

Resolves: GREG-88

- Rename management command start_notification_publisher to notification_publisher
- Rename management command start_schedule_tasks to task_scheduler
- Stop using python-daemon and lockfiles, as these will run as standalone containers anyway
- Remove management commands stop_notification_publisher and stop_schedule_tasks
- Remove python-daemon dependency

- Expanded output from guest info api endpoint
- Share guest info between both routes under /sponsor of the frontend.
- More localised text options added for use on the sponsor pages
- Details button on the sponsor overview page now points to the guest
  info page for each person.

Resolves: GREG-74

Enable testing for gregui

Issue: GREG-66

Issue: GREG-66

- Introduces the Invitation and InvitationLink models for keeping track
  of guest invitations and the links connected to them.
- Adds a post endpoint accessible by sponsors to create invitations for
  guests.
- Adds a get endpoint for the guests to review their invitation
  information.
- Adds a post endpoint for the guests to confirm their invitation with
  updated mobile_phone number if they want.
- Removes token field from Person since it is not used.

Make all URLs relative. Move /oidc and /admin endpoints up from /api and proxy them during development.

Add a Containerfile for the frontend. Allow configuration to be injected. Move static files directory for Django.

Just print mails to console instead so no one sends real emails on accident

Issue: GREG-42

Issue: GREG-42

Register page now fetches OUs the sponsor has access to.
Sponsor page now shows the sponsor's active and waiting guests.

Resolves: GREG-63

Issue: GREG-36

Issue: GREG-36

Issue: GREG-36

Issue: GREG-36

Issue: GREG-35

The Django configuration expects a static directory to be present
on the file system, otherwise the tests will output a warning.  This
adds an empty directory using the clever git trick of ignoring
everything within the directory except the .gitignore file itself.

This silences a warning during the test run.

Fixes: GREG-14