- Fix landing page
- Introduce and use SelectRelatedEvent for centralising the logic of
  finding and showing related LogEntries. It also clears the selection
  of all list panels if there are no related entries.
- Add "select related" button to the script-panel to show events only
  from the currently selected script
- Add selection type tabs for the map-panel
- Fix transition colors for map-transitions view
- Introduce separate map-transition view for the currently selected Map

Bug: v8:10644
Change-Id: I4199a8332bab2518d98078712ed5ce9a8f1dc19e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2599555
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71849}