reproducible: _html_indexes: start to use the new Status enum instead of...

reproducible: _html_indexes: start to use the new Status enum instead of passing around plain strings

this highligted some inconsistencies between the various statuses.
Those are highligted by #XXXs and #FIXMEs, and will need db changes
couples with a careful review of pretty much everything.

Signed-off-by: Mattia Rizzolo <mattia@debian.org>