Send request body for http client integrations and similar

[adinauer]

Different SDKs have different HTTP library integrations.
We plan to generate events directly from these integrations when we detect failed HTTP response status code.

• Capture event for HTTP requests resulted in server error #38

Additionally, we can attach the request and/or response bodies. This feature exists in some for in some SDKs, we'd like to discuss in a broader SDK group and define details and write the develop docs.

• Check which integrations already do it. Add checklist with integrations with their status.
• Amend develop docs. We have the current develop docs direction for HTTP library integrations
  • Maybe it should be done via attachments?
  • it doesn't say anything about Request or Response body.
  • It currently has no note regarding PII.
  • Add docs on how to deal with gotchas, how to strip data in callbacks etc.
• Public facing docs should be written under common and opt'ted-in in platforms that support it as we go.

SDKs:

• Dart

[marandaneto]

This requires an RFC since it should be an attachment instead of a data field in the event protocol, PII concerns, etc.
Relates to getsentry/sentry-dart#624 (comment)

[mattjohnsonpint]

JavaScript SDK: getsentry/sentry-javascript#7287

[mattjohnsonpint]

• .NET: Add options to capture HTTP request and response from HttpClient sentry-dotnet#2218

[jamescrosswell]

I see this was moved from blocked to backlog back in June. However it looks like some key design decisions still need to be made before we could start work:

• Mainly we need to decide whether the bodies would be added as attachments... my 2c:
  • This should be consistent with how we capture the payload when handling server requests in ASP.NET Core
    • Currently captured in the request/response interfaces on the transaction
  • Whatever we do here we presumably also want to do for GraphQL Clients and Servers as well
• Ideally the develop docs would be updated summarizing key decisions comming out of the above discussions