Values of fields now show the current dates of the role after data has
been fetched, instead of the placeholders.

Comments and contact person had feature flags created for their
visibility some time ago, but we missed a couple of sections in the
frontend. In addition, comments that were set on a role during
invitation was invisible later, defeating the purpose. They are now
visible if comments are enabled.

Resolves: GREG-197

Necessary for OUs and RoleTypes with missing english or norwegian names

The page relied on the visitor having gone to one of the other sponsor
pages before going to it. By setting some default values for the role
info the page now works if you go directly to it. Should probably
restructure this page to display a loading graphic if a future version
of the app is ever created.

Resolves: GREG-184

Resolves: GREG-177

Roles that have started could not be given start dates in the past in
the frontend. After this fix they now can.

Dates can now be changed after they have started and ended. This means
that there is no situation which needs disabling the input fields, and
disabling has been removed.

Start and end date can now be in the past. The following rules apply:
 - Start dates can be any date in the past, and no more into the future
   than the max days property of the role type.
 - End dates follow the same rules
 - End dates must be equal to or later than start date.

Notification publishing has been reviewed to ensure duplicate
notifications are not created when start or end date is today.

Resolve: GREG-148

- The hook returns the info for a single guest, and a function to reload
  that info from the api.
- The roles of the guest are now on the roles attribute of the guest
  object instead of as its own object.
- Adding a new role now triggers a reload of the data from the api after
  the post request has completed.

Resolves: GREG-114

Code for guest routes moved to their own folder so that we don't need
multiple api calls.
Serializer class for roles has been simplified with methods for
validation of each field and a separate one used in invites without
requiring the person field.

Resolves: GREG-61

To make handling info about roles and persons easier we split them into
separate objects. The Profile page has now gotten its own api endpoint
where a sponsor has access to all guests instead of only those they are
sponsor for which is used on the sponsor frontpage. This is necessary
since a sponsor may want to give a role to someone they are not
currently sponsor for.

Allows changes to start- and end date for guest roles. A new endpoint
has been added to the ui api for doing PATCH request to support this.
The max days of each role type is respected.

Resolves: GREG-83