fix(remix): Attempt to extract user IP from request headers.

[onurtemizkan]

Ref: #6139 - #6139 (comment)

Remix requests don't contain client IP addresses in req.ip or req.socket.*.
To extract them, we need to iterate over a set of request headers that may contain that info.

I have vendored / modified an implementation of that function from third-party utility set remix-utils. (Using as a dependency is not possible because of incompatible TS syntax.)

It's still the best effort and may also need improvements over header key prioritization.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.5 KB (-0.02% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	60.29 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.16 KB (-0.02% 🔽)
@sentry/browser - ES6 CDN Bundle (minified)	53.63 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	19.9 KB (0%)
@sentry/browser - Webpack (minified)	65.12 KB (0%)
@sentry/react - Webpack (gzipped + minified)	19.92 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	45.93 KB (0%)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.37 KB (0%)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	24.78 KB (+0.01% 🔺)

[lobsterkatie]

Looks good!