Refactor from_csv jinja filter
Refactor from_csv jinja filter

Old filter doesn't work with python3. The new one works in python2 as
well as python3. Additionally it's based on modern python paterns so
it's more clear to understand.

Change-Id: I9827296da9062c50e52d994194de8e4086d9db80

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared