[Sidekiq] Display stringified version of globalid

[louim]

Hey!

I'm not sure if that's the right place to ask, but it would be useful if the Sidekiq context:
https://github.com/getsentry/raven-ruby/blob/14fd97f84f218a8ff16024aadea3430eb1dd169f/lib/raven/integrations/sidekiq.rb#L24
would include the .to_s version of globalid when such key is present.

How it currently look:

That object reference isn't much help when debugging a problem. The original gid://elite/Contractor/1040 globalid string would be much more useful.

Would that make sense?

[nateberkopec]

Yes, that makes sense. Not my top priority but would accept PR 👍