[WIP] Assessing responsibilities of the library for downstream I/O

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Should this be more of a sans-io project?</issue_title>
<issue_description>This library intentionally doesn't do any I/O. It expects downstream libraries to add the I/O. But this isn't really a "Sans-IO" project in the sense that there are still aspects of the protocol that are ignored, such as the JSON RPC framing (especially multiplexing commands and handling errors). Should this project absorb some more responsibility to simplify downstream implementations?</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Should this be more of a sans-io project? #12

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