Method Call execution should not block server's execution
Description
Currently, method calls callbacks are called by the Services thread (they are executed by the service handler call_method_bs__exec_callMethod
).
This effectively blocks the server's service treatment until the method call is finished, and can alter the performance.
It also prevent the callback from using local services, such as synchronous reads.
Analysis
The server could push the callback execution to the Application thread. This requires the creation of new internal events to push the received request to the application thread and forward the result to the client which called the service.
See also #816 (closed).