Trace State trace_id incompatible with transaction trace_id

[rhcarvalho]

The new Trace Contexts page documents a trace_id that is a UUID, while in the Performance product we do not use UUIDs (neither for trace_id nor span_id).

Reference:

https://develop.sentry.dev/sdk/event-payloads/transaction/#anatomy

trace_id:
Required. Determines which trace the Span belongs to. The value should be 16 random bytes encoded as a hex string (32 characters long).