Add support for addUser/inviteUser

[bamse16]

Hi team,

Please add support for the /portals/self/invite endpoint.

• params:

{
    invitations: [
      {
        email,
        firstname,
        lastname,
        username,
        password,
        role,
        userLicenseType,
        fullname,
        userType,
        userCreditAssignment: -1,
        applyActUserDefaults: false
      }
    ],
  };

• response

{ success: true, notInvited: [username, ...] }

Also if a user was not added, please include the reason why that was not possible.

The current API returns success: true, notInvited: [username], however no reason why that's not possible is included.

Regards,
Marius