Add "Query Sources" Ruby support

[gggritso]

Problem Statement

Query Sources are supported in Python frameworks and in Laravel, but not in Ruby. Opening this issue so we can keep track of customer requests, which have come up a few times already.

Solution Brainstorm

There's some prior art on this in our own SDKs and in the OSS world, since Rails has built-in query source collection. Maybe we can hook into that, or just do something similar.

Product Area

Performance - Queries

[getsantry]

Routing to @getsentry/product-owners-performance for triage ⏲️

[leoplct]

+1. This would be very useful. ScoutAPM support it. Maybe you could use Rails instrumentation.

[swanson]

We are trying to consolidate our tooling on Sentry, but this is a big loss in moving from Scout. Happy to help with beta testing.

[sl0thentr0py]

will prio this soon