Jormun: add status api for jormungandr

add a status api to have the jormungandr version and all the instances
status

Mainly for supervision

Note: must be merged after #675 to have the jormungandr version
it should be
```c++
const char* const argv[] = {"bob",
                            "--GENERAL.instance_name=default",
                            "--GENERAL.zmq_socket=42",
                            nullptr};
```