This is consistent with what we expose via the API, where we never tried
to hide this data. It was effectively only hidden from the UI.
We couldn't come up with a reason why it was hidden from the UI back then,
but since we now needed to expose updated_at to everyone (previous commit),
it only made sense to consistently also allow created_at to be seen by everyone.
Favorite is the correct term in the context of expressing a preference
for a particular project / other OpenProject domain object.
Updates `ActsAsFavorable` to `ActsAsFavoritable`, as well as filenames,
identifiers and strings to:
favored => favorited
favorable => favoritable
favoring => favoriting
Dombi Attila