Adding missing contact person field on form

See merge request !142

Adding a validation check for role start being before role end date

See merge request !141

Rate limit invite endpoint

See merge request !134

To prevent hammering on the invite endpoint we throttle requests to the
endpoint to 100/day per ip.

Resolves: GREG-84

Greg 93 fixtures

See merge request !130

Adds support for importing extra indentifies from orgreg

See merge request !138

GREG-103: Fixing issue where passport information was not saved

See merge request !139

To make testing of the frontend easier, we add a script that generates
Person objects with the appropriate Consents and Identities for the
different stages of the registration process. This includes Invitations,
InvitationLinks, Sponsors and other things that would be present in a
production environment.

Resolves:  GREG-93

The status column now signifies if the role on that line is active or
not.

Greg 90 safer invites

See merge request !133

Introduce OuIdentifiers

See merge request !128

Greg 73 mail templates

See merge request !132

To prevent the invite id from showing up in various logs along the way,
we change to use an anchor in the invite url, and a post request to the
backend.

Invite links are now on the form /invitelink/#<uuid> and the frontend
redirects to /invite as usual after the session has been created.

Resolves: GREG-90

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

Even though start_date can be optional in the payload, it will always be
present in the form.