Support for spans and tracing

[mooreds]

Adding in span/tracing support helps sophisticated users debug requests using tools like Honeycomb or other open telemetry compatible tooling.

Related

• FusionAuth tracing issue: https://github.com/FusionAuth/fusionauth-issues/issues/1665
• OpenTelemetry HTTP request conventions: https://opentelemetry.io/docs/specs/semconv/http/http-spans/
• Netty doc: https://projectreactor.io/docs/netty/1.2.6/reference/http-server.html#tracing
• Setting up opentelemetry in tomcat: https://uptrace.dev/guides/opentelemetry-tomcat

[robotdan]

Thanks @mooreds - I think this would be a great addition. I'll take a look.