[debugger] Rewrite the ScopeIterator/DebugEvaluate to use Scope rather than ScopeInfo for inner scopes.

This CL also bottlenecks all current scope handling in the ScopeIterator, and cleans up frame handling in debug-frames and the deoptimizer.

Change-Id: I061922a356ce17794262f8d77d5d7c824558fc50
Reviewed-on: https://chromium-review.googlesource.com/1095094
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53741}