Bug 30982: Adapt table to new API spec

Bug 30982: Adapt table to new API spec

Disclaimer: this patch is highly opinionated :-D

When I started looking at this patch I felt like the two tables
(current/past jobs) implemented on bug 30462 was the way to go.

In order to make this patches apply after it I had to redo all the
things. Or most of them.

But I decided to keep the idea of filtering out completed tasks, not
just having the option to display 'the last hour' tasks. For the task I
added some required helper methods and the relevant tests as well. So a
behavior change.

Hope you all agree with it.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>