Add tracing metrics to oxd server

How to enable tracing metrics in oxd server

1. Download and run jaeger locally or on server from : https://www.jaegertracing.io/download/ Jaeger can be run locally/on server directly using Docker: docker run -d -p 5775:5775/udp -p 16686:16686 jaegertracing/all-in-one:latest

2. In oxd-server.yml set following properties for tracing.

**enable_tracing** - set this property to "true" to enable tracing.
**tracer** - mention tracer whether "jaeger" or "zipkin".

**tracer_host** - mention tracer host

**tracer_port** - mention tracer port

1. Start OXD server. Now server can be monitored at jaeger on url : http://:16686