chore: Introduce internal getHubAndIntegration

[mitsuhiko]

This is trying to replace the combined used of getCurrentHub and getIntegration with a utility getHubAndIntegration. The desire here is code that's easier to read and understand as well as slightly easier to minify.

This does not yield the intended results like this, so I would not merge it for size reasons. However I think overall combined with other refactorings this would be a sensible change.

[github-actions]

size-limit report

Path	Base Size (7e0a307)	Current Size	Change
@sentry/browser - CDN Bundle (gzipped)	21.41 KB	21.49 KB	+0.38% 🔺
@sentry/browser - Webpack	23.2 KB	23.26 KB	+0.26% 🔺
@sentry/browser - Webpack - gzip = false	81.27 KB	81.42 KB	+0.19% 🔺
@sentry/react - Webpack	23.24 KB	23.3 KB	+0.26% 🔺
@sentry/nextjs Client - Webpack	47.83 KB	47.92 KB	+0.19% 🔺
@sentry/browser + @sentry/tracing - CDN Bundle (gzipped)	29.73 KB	29.79 KB	+0.23% 🔺

[mitsuhiko]

Closing this. If we want to revisit, I would redo this.