Merge endpoints for SAM

[BGWoodward]

It would be ideal to only have one endpoint, with the same call signature, similar to the response signature. We do not enforce any schema on the response, but rely on the response to be introspectable JSON for the caller to handle. Similarly, it is desired to do the same thing on the input, by adding a metadata field that can hold generic JSON, which will initiate control flow statements in the function itself for deciding where to route the request.