more turbopack HMR fixes and test case (#55368)
### What?
improve test case to check HMR
reenable deduplication for server side hmr events
add aggregation of client side HMR events
### Turbopack Changes
* https://github.com/vercel/turbo/pull/5936 <!-- Will Binns-Smith -
Update http mock and clap -->
* https://github.com/vercel/turbo/pull/5948 <!-- Tobias Koppers - CSS
HMR fixes -->
Closes WEB-1557
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Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>
