This method returns the unique debugger ID for a v8::Context (i.e. the
V8DebuggerID), serialized to a pair of int64_ts.

Bug: v8:12528
Change-Id: Ib2cdda73447f8233f9afb773fed4a634d4618aef
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3369124Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Alex Turner <alexmt@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78958}