Instrument with Open Telemetry to replace the current logger interface

[pipex]

Mahler currently provides a Logger interface to provide visibility into the planning and execution processes. This interface is very restrictive and does not provide structured logs. We would like to standardize this output to provide better observability into when the agent is planning, what is the resulting plan, what action is being executed, what changes are happening during the task execution, etc. This will make it easier for users to generate whatever messaging they want from the trace output/.

Using the opentelemetry API will allow us to do that

[pipex]

In Mahler v4, the logging interface was formalized which makes this mostly unnecessary