Add a ThrowError helper to encourage throwing full Error objects
instead of just v8::Strings.

Bug: v8:11195
Change-Id: I15d75b1d39b817de3b9026a836b57a70d7c16a28
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2811738
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73958}