Update publication date of draft reviews on CritiqueBrainz when they get published
A review on CritiqueBrainz can be initially saved as a draft before it is finally published. The review is created, however, it is not published. Later, when the user is satisfied with the review, the saved review is updated.
Presently, the publication date of a review is the same as the date when the review was first saved as a draft. Instead, the publication date should be updated when the reviewer actually decides to publish it.