[Bug] Update parallel interface to work with uncertainty interface

[paulf81]

Update parallel interface to work with uncertainty interface

Working my way through #830 I noticed that parallel_computing_interface.py still has functions set for the old uncertainity_interface, wanted to flag this should be fixed with some steps:

• Make sure we still want the names parallel_computing_interface and uncertainity_interface given Rename floris.simulation, floris.tools to floris.core, floris #830
• Add test of parallel_computing_interface + uncertainity_interface
• Update calls (don't use unc_pmfs for example)

[misi9170]

Closed by #830