Add the ability to transform between sse/streamable-http to stdio

[yrobla]

In order to support Claude Desktop, we need to have a way to run all mcp servers with stdio transport, as it's the only one supported for now https://www.anthropic.com/engineering/desktop-extensions

There are many hacks and ways to achieve it, also several projects offering this feature. It would be very interesting to have this conversion for toolhive as well. Only focusing in sse/streamable-http to stdio

To achieve that we could use the fact that we are already inspecting traffic in transparent proxy, to do this transformation (adding a flag to run : --convertToStdio, --outputToStdio, etc)