bun: Bun.serve does not capture request bodies #23884

Deno calls captureBodyFromWinterCGRequest and Cloudflare calls captureIncomingRequestBody. Bun calls neither, so dataCollection.httpBodies and maxRequestBodySize have no effect on Bun.serve routes.

bunserver.ts:236 also builds normalizedRequest by hand rather than using winterCGRequestToRequestData, which is what Deno and Cloudflare use. Worth checking that header scrubbing matches.

Work item. Use winterCGRequestToRequestData and captureBodyFromWinterCGRequest in bunserver.ts.

**Prior art **(related history only). No issue for Bun. The Deno equivalent shipped as #22912 (merged, maxRequestBodySize for Deno HTTP bodies) and is the model to copy.