Mesmer as OTEL Agent Extension

[lgajowy]

The below document proposes an approach where we stop using a custom Mesmer agent and fully rely on the Opentelemetry's java agent:

https://docs.google.com/document/d/1BYVviTkfbHQttuAtGEXMQRKHF7tGKrgc77zue5ibvqg/edit?usp=sharing

Any comments are welcome both here and in the document.