[python] new plugin for python runtime

Python runtime details are required for developers for various
diagnostic and development purposes. Collect the Python version of the
'python' executable.

Signed-off-by: Poornima M. Kshirsagar <pkshiras@redhat.com>
Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
[python] add package check and make portable

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>