Dashboard Updates: UX / CI improvements and Lab consistency.

Hello KernelCI community,

We have deployed a few updates and fixes to the dashboard. You can
check out the live site here: https://dashboard.kernelci.org.

 UX
    • Trees now have a Compare page: pick two checkouts and see status
summary counts, plus builds, boots, and tests that were added,
removed, or changed status between A and B.
    • Issue details now show first/last seen per tree, and a link to
the first good checkout after the issue appeared, so you can tell
whether a failure is tree-specific and where it cleared.
    • Cosmetic enhancements on the commit history plot.
    • Bugfix on tests table to keep column widths stable while sorting
and paging.
    • Bugfix on stale frontend cache. Avoiding frontend crash on schema updates.
    • Hardware revision selectors work correctly for cross-origin builds/tests.

  BACKEND
    • Builds and tests are now tied to labs in the database, so lab
filtering and display should be more consistent as data backfills.

CI
    • Schema migrations are safer on large shared Postgres, a timeout
for lock avoid that new deploys cause a lock contention on production
database.

  Best,
  Alan Peixinho
  KCI Dashboard Team