[2.3, UI, HWTv2] When upgrading from older MAAS, Storage HW tests are not mapped to the disks

[Andres Rodriguez]

After an upgrade from 2.2 to 2.3, the hardware tests section under storage have two sections:

1. Section for each of the disks, that shows the tests for the specific disk.
2. Section without any specific disk, that shows the tests that were run before knowing to which disk.

This is bad design and is really confusing. As such, what should happen is:

The old tests results (not attached to a storage device) should all be part of "previous" tests for all the disks. In other words, since the old tests were run across all disks, then this are effectively results for all disk and should be shown under each of the disks, and not in its own section.

Further, there's another issue. I have 2 tests run on 2.2 and 2 test in 2.3 MAAS:
 - In the machine listing on the disk section, I see: 2 tests have passed, 2 tests have failed.

The failed tests come from the fact that they were run in 2.2 MAAS.