Add sentry_link for GraphQL

[ueman]

📜 Description

Resolves #1126

💡 Motivation and Context

Context: #1126 (comment)

💚 How did you test it?

It's already used widely in production without any reported issues

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
• I updated the docs if needed
• All tests passing
• No breaking changes

🔮 Next steps

• Hand over the ownership of the https://pub.dev/packages/sentry_link package on pub
• Add CI for this new package (I would like to hand this task over to you)
• Rename the folder from sentry_link to just link or graphql?

Open questions

• What to do with the changelog? All other packages reuse the same one
  • Changelog has been moved and linked
• What to do with the license? I'm happy to change it

I'm happy to discuss this via Discord, Twitter, E-Mail, or whatever :D

[buenaflor]

thx!!

I wonder how we are going to port the existing changelog since we symlink the main changelog in our packages and I don't necessarily want to remove the existing graphql changelog

[ueman]

Yeah, I've wondered the same. Maybe keep it as CHANGELOG_OLD.md and then just link once from the shared one to it?

E.g. add the following to the new changelog:

### version xxx

- Transfer ownership to Sentry. To see the old changelog from previous versions go to [here](link/to/old/changelog.md)

or something like that.

[buenaflor]

thx, will get to this PR once the next sentry flutter release is out