[test] Add source-mapping coverage of React's fake stack frame scripts in `use cache` (#95945)
Adds tests verifying that`use cache` stacks get symbolicated.
We noticed insufficient coverage in
https://github.com/vercel/next.js/pull/95936, which should have failed
the tests (it broke symbolication) but tests passed. So this restores
the missing stack assertions. This also adds some new coverage that
specifically verifies that symbolicating via CDP also works.