Remove the one-argument Handle constructor and "handle" factory method,
replacing them with Isolates where available and GetIsolate() methods
otherwise.

TBR=verwaest@chromium.org

Bug: v8:7786
Change-Id: I8ee92ef727c05382c984a3e4c290198d0b312619
Reviewed-on: https://chromium-review.googlesource.com/1113542Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54025}