Document new integration jobs

This PR documents the recent changes brought to the OMERO.web integration test framework by @chris-allan. The nex layout of the integration suite is described with the new collection jobs and extra information is added regarding the location of the test results.

--depends-on https://github.com/openmicroscopy/openmicroscopy/pull/2319
--depends-on https://github.com/openmicroscopy/openmicroscopy/pull/2349
--no-rebase