Fix service call

[aremazeilles]

The main fix is related to the verification of services with input that are not basic format (like ROS format).

The error is related to that call:

srv_resp = srv_proxy(**srv_input)

which converts input dictionary into a set of input parameter to the function.
This only works if the service input only contains basic format, like int, bool etc.
If an item is itself a composed ROS message format. It fails.

The solution is to do the following:

srv_type = rosservice.get_service_type(srv_name)
req = message_converter.convert_dictionary_to_ros_message(srv_type, srv_input, kind='request')
srv_resp = srv_proxy(req)

The input dictionary is concerted into a service request, and the proxy is triggered with this unique input parameter.

Several linting fixes also inserted.