feat: caller headers forwarded to the outbound traffic
Enabled called header propagation on services outbound traffic. default forwarded fields are (ref):
- x-correlation-id
- x-variant-id
- x-feature-flags
- x-request-id
- x-b3-traceid
- x-b3-spanid
- x-b3-parentspanid
- x-b3-sampled
- x-b3-flags
- x-ot-span-context
The default forward configuration can be changed, by specifying the list of headers to forward in the env variable CALLER_FORWARD_HEADERS as comma-separated strings list, no spaces