Add W3C trace context support to Sentry

### Problem Statement

Sentry currently implements its own headers for traces, but the python implementation does not implement a set of W3c trace context compatible headers. This means that other systems receiving data enriched by Sentry have to figure out the trace parent by themselves instead of relying on standard implementations.

### Solution Brainstorm

https://github.com/getsentry/sentry-dotnet/pull/4084 already implements this for the dotnet SDK if I understood correctly. It would be nice if the python SDK could also do this.