Track `use cache` usage (#75007)
We’re updating the SWC transform to
[track](https://nextjs.org/telemetry) how the "use cache" directive is
used during builds. Each use of "use cache" is counted based on the
handler it’s linked to.
By default, "use cache" counts toward a feature called
"useCache/default". If a custom handler is defined in the Next.js config
(e.g., "custom"), then "use cache: custom" will count toward
"useCache/custom".
The build process will collect these counts and combine them across all
source files and workers. This data is reported under the
NEXT_BUILD_FEATURE_USAGE event, allowing us to filter by "useCache/*" to
see how often each cache handler is used.
*Only support webpack prod build for now.
Closes NDX-683
