no-issue
Because we were checking for truthyness rather than existence when
updating properties on an Offer - it was impossible to set the
description to a blank string, as this is falsy.
refs https://github.com/TryGhost/Team/issues/1131
- Includes `status` on OfferDTO so client can use it
- Allows editing `status` of Offers
- Allows setting initial `status` when creating Offers