This is the second step towards moving away from sending `url` with
every call frame when emitting the `Debugger.paused` event.

Bug: chromium:1270316, chromium:1271078
Change-Id: Ib4f996024b5200cded155bd8a564d01d36856400
Doc: https://bit.ly/devtools-debugger-callframe-url
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3431485
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78906}