ref: Hoist RequestData integration to @sentry/core

[lforst]

This PR hoists the RequestData integration into @sentry/core and all of its utility functions into @sentry/utils. In the process of this, I ended up merging the two versions of the requestdata.ts utility files we had (one in node and one in utils) to just leave us with the one in utils.

We need to hoist the RequestData integration to be able to use it in different runtime SDKs other than node.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser (incl. Tracing, Replay) - Webpack (gzipped)	66.02 KB (+0.12% 🔺)
@sentry/browser (incl. Tracing, Replay) - Webpack with treeshaking flags (gzipped)	56.1 KB (+0.14% 🔺)
@sentry/browser (incl. Tracing) - Webpack (gzipped)	31.1 KB (+0.27% 🔺)
@sentry/browser - Webpack (gzipped)	21.41 KB (+0.39% 🔺)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (gzipped)	62.42 KB (+0.1% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (gzipped)	29.23 KB (+0.29% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped)	21.35 KB (+0.35% 🔺)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (minified & uncompressed)	196.93 KB (+0.16% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (minified & uncompressed)	88.74 KB (+0.35% 🔺)
@sentry/browser - ES6 CDN Bundle (minified & uncompressed)	63.71 KB (+0.49% 🔺)
@sentry/browser (incl. Tracing) - ES5 CDN Bundle (gzipped)	31.96 KB (+0.3% 🔺)
@sentry/react (incl. Tracing, Replay) - Webpack (gzipped)	66.31 KB (+0.12% 🔺)
@sentry/react - Webpack (gzipped)	21.45 KB (+0.39% 🔺)
@sentry/nextjs Client (incl. Tracing, Replay) - Webpack (gzipped)	83.08 KB (+0.11% 🔺)
@sentry/nextjs Client - Webpack (gzipped)	48.25 KB (+0.18% 🔺)
@sentry-internal/feedback - Webpack (gzipped)	16.19 KB (+0.55% 🔺)