- Changes IJsonRpcMessage to an abstract base class so RelatedTransport will always be available
- Streamable HTTP supports multiple concurrent HTTP request with their own indpendent SSE response streams
- RelatedTransport indicates the source or destination of the JsonRpcMessage
- Changes the default RequestId to a JSON number for better compatibility with MCP servers in the wild
* AI generated `///` comment updates
* Fix compilation issues
* Fix incorrect XML comment structure
* Update all Client comments
* Update all Configuration comments
* Update all Messages comments
* Update all Transport comments
* Update all Types comments
* Update all Server comments
* Undo some commenting
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Co-authored-by: Stephen Toub <stoub@microsoft.com>