:sig
String ws_message()

:params
return value : payload of the current WebSocket message

:see
>websocket

:content
Returns the payload of the current WebSocket message being handled by `WS(Request& context)`.

For text frames this is the decoded text payload. For binary frames this `String` contains the raw message bytes.

Use `ws_is_binary()` or `ws_opcode()` to choose how to parse the payload.

:example
print("ws_message is resource-bound; configure the service or connection, then call it in request code.\n");
