Default Run Duration and Run Schedule should be modified for Python source processors

Currently the default Run Schedule for Python processors is 0 sec and the default Run Duration is 25 ms.
It is common use-case for a source-type processor to run once periodically instead of running continuously. Therefore - just like in case of List* processors - the default Run Schedule should be set to 1 min.
To make sure that the processor is only triggered once in every cycle, default Run Duration needs to be set to 0.