ref(replay): Add further logging to network body parsing

[mydea]

We got somewhat closer to figuring out the problem there. Based on this comment: #9339 (comment)

The requests are now showing with the request body, but the response body is "undefined"

It seems that the problem is with parsing the response body for a XHR request. I added some more logging there, to be able to debug this further.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser (incl. Tracing, Replay) - Webpack (gzipped)	65.47 KB (+0.08% 🔺)
@sentry/browser (incl. Tracing, Replay) - Webpack with treeshaking flags (gzipped)	55.63 KB (+0.02% 🔺)
@sentry/browser (incl. Tracing) - Webpack (gzipped)	30.98 KB (0%)
@sentry/browser - Webpack (gzipped)	21.3 KB (0%)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (gzipped)	61.95 KB (0%)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (gzipped)	29.1 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped)	21.24 KB (0%)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (minified & uncompressed)	195.42 KB (0%)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (minified & uncompressed)	88.32 KB (0%)
@sentry/browser - ES6 CDN Bundle (minified & uncompressed)	63.3 KB (0%)
@sentry/browser (incl. Tracing) - ES5 CDN Bundle (gzipped)	31.81 KB (0%)
@sentry/react (incl. Tracing, Replay) - Webpack (gzipped)	65.82 KB (+0.09% 🔺)
@sentry/react - Webpack (gzipped)	21.34 KB (0%)
@sentry/nextjs Client (incl. Tracing, Replay) - Webpack (gzipped)	82.54 KB (+0.07% 🔺)
@sentry/nextjs Client - Webpack (gzipped)	48.13 KB (0%)
@sentry-internal/feedback - Webpack (gzipped)	16 KB (0%)