[sources] Migrate CallStackSidebarPane to new StackTrace

This CL changes the CallStackSidebarPane to create a fresh StackTrace
instance on every pause. Rather then creating a LiveLocation for each
frame and updating them in-place, we listen for UPDATE events and
just re-render the whole pane.

This is not necessarily more expensive: An UPDATE event comes only
once when e.g. a new source map is attached, not separately for
every frame.

To make this work, we need to disable the "expandCallFrame"
callback from the language plugin. This is handled by the
'translateFrameStep' cleanly now.

Follow-up updates can remove the "expandCallFrame" layering
violation as well as "createCallFrameLiveLocation".

R=pfaffe@chromium.org

Fixed: 465879478
Change-Id: I334955fbc5e6da0e326f9da5fd4ea21c616670bb
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/7531559
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Philip Pfaffe <pfaffe@chromium.org>