Disconnect clients who send ill-typed or unparseable function args

We generally rely on clients having a correct and up-to-date schema. A clear indication they do not have such a schema in the form of an ill-typed function call request means that we cannot correctly interoperate with that client. Even if some of the client's other messages may incidentally succeed processing, we should not assume them to be processed correctly. As such, the SpacetimeDB server should disconnect any client that sends an ill-typed function call along a WebSocket connection.

Note that our SDKs already behave according to this theory; they will error and disconnect when receiving row data they cannot parse from the server.