feat(perf-issues): Add CLI script for testing detector output

[gggritso]

Adds a CLI script for testing our detection. Very handy for testing detectors on user-supplied events in JSON format.

N.B.: This makes a small logical change! Instead of iterating through the spans one-by-one, and sending each one to each detector, it iterates through the detectors, and sending the detector spans one-by-one. Subtle change, doesn't change the output.

e.g.,

~/C/s/sentry (feat/add-cli-detector-tooling) sentry performance detect ~/Desktop/fc6ef7f890b84657a6c575c06ff9caef.json
{'fingerprint': '1-GroupType.PERFORMANCE_N_PLUS_ONE_DB_QUERIES-bac638c481f0d0ddb4773cf0dd80f656a0abfde1', 'op': 'db', 'desc': 'SELECT "product_details".* FROM "product_details" WHERE "product_details"."product_id" = $1 AND "product_details"."name" = $2 L.... etc

[udameli]

cool idea!

[gggritso]

@k-fish @mjq-sentry any concerns about this one before I merge it? I don't see how the change in span iteration order would cause any issues, but feeling a little paranoid about it

[k-fish]

@gggritso nothing stands out to me, just reversing from nm to mn.