Add child_spans for Sidekiq Queue instrumentation

[frederikspang]

Implements #2322 for Sidekiq.

Description

Adds support for Sentry Queues page (With predefined span op names)

https://docs.sentry.io/platforms/ruby/guides/sidekiq/tracing/instrumentation/custom-instrumentation/queues-module/

[rwojsznis]

Oh wow, exactly what I was looking for 😅 🙌

can we somehow help to get this shipped? 💪

[solnic]

Thanks for working on this! 🙇🏻 Would you be able to add some basic specs for this too?

[frederikspang]

@solnic I've added two basic specs.
Latency is a bit difficult, without introducing some timecop kind of tool. Which we do have in sentry-ruby, so we could just introduce it here if we wanted to.

[frederikspang]

@solnic After looking at these, I think queue.process may actually replace op: queue.sidekiq instead of being a child span.
They will always be redundant - But we should set origin or some other field to sidekiq, description or name maybe, to differentiate the processor. (ie. using another processor alongside Sidekiq - or doing queries in Sentry UI across applications)

[nateberkopec]

Looks like it needs a changelog too

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.18%. Comparing base (9bba2ef) to head (fad677a).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2403   +/-   ##
=======================================
  Coverage   98.18%   98.18%           
=======================================
  Files         126      126           
  Lines        4726     4735    +9     
=======================================
+ Hits         4640     4649    +9     
  Misses         86       86           

Components	Coverage Δ
sentry-ruby	98.51% <ø> (ø)
sentry-rails	97.20% <ø> (ø)
sentry-sidekiq	97.58% <100.00%> (+0.10%)	⬆️
sentry-resque	92.85% <ø> (ø)
sentry-delayed_job	95.65% <ø> (ø)
sentry-opentelemetry	99.31% <ø> (ø)

Files with missing lines	Coverage Δ
...iq/lib/sentry/sidekiq/sentry_context_middleware.rb	98.07% <100.00%> (+0.40%)	⬆️