This CL maximises the space use in between panels and
fixes asymmetries in the Web app to make the UI panel
views more compact and increase accessibility of the
web app for different screen size.

Bug: v8:10644

Change-Id: I07bf6317db2cf3fa59204120276f0f885e356e6c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2351660Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Commit-Queue: Zeynep Cankara <zcankara@google.com>
Cr-Commit-Position: refs/heads/master@{#69358}