Add tracing instrumentation

[lmineiro]

Tailor is often used as part of large-scale distributed systems and providing out of the box tracing support will extend the observability already present.

Opentracing has gained enough traction and community support to be considered the current standard way of providing distributed tracing across polyglot systems.

The goal of this issue is to instrument the basic operations first, preparing the environment to provide a global tracer which can later (with separate issues) be used to instrument all other missing operations.

[vigneshshanmugam]

closing in favor of #232 #236