[core-http] Separate serialization/deserialization from mapping

[xirzec]

Pipelines should be able to intelligently serialize/deserialize for wire transmission without this process being tied to mapping or any other kind of response parsing or request formatting.

[xirzec]

Have to think about this some more, might want to wait until we move away from OperationSpec

[ramya-rao-a]

Moving to Backlog milestone as we don't have plans to get to this in the current milestone or the next

[github-actions]

Hi @xirzec, we deeply appreciate your input into this project. Regrettably, this issue has remained inactive for over 2 years, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.