feat(spans): extract user.geo.geoscheme metrics #14891

Job	Run time
Lint	2m 4s
Test (macos-latest)	2m 7s
Lint Rust Default Features	1m 24s
Test (windows-latest)	1m 52s
Setup build metadata	1s
Test All Features (ubuntu-latest)	2m 7s
Integration Tests	2m 5s
Test Python	1m 0s
Build Relay Binary (relay, x86_64-unknown-linux-gnu)	1m 59s
Build Docker Image	1s
Publish Relay to DockerHub	1s
Publish Relay to GCR	1s
Upload build artifacts to gocd	1s
Sentry-Relay Integration Tests	1s
self-hosted-end-to-end	1s
	14m 45s

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