lister: Type correctly the 'indexable' column
instead of converting that column as a string
As a side effect, bitbucket wise, we provided improperly the after query parameter as a date not url encoded. This resulted in improper api response from bitbucket's (we received from time to time the same next index as the current one).
Related #1826 (closed) Depends on !375 (closed)
Migrated from D1634 (view on Phabricator)