Update for new OpenDSSDirect

[mnblonsky]

There are likely many updates to OpenDSSDirect.py that haven't been incorporated here. We'll need to review the changes, possibly since v0.6.1, and make some improvements. For now, the only one I know of is:

• use dss.Text.Command() in the run_command function

If anyone else has suggested changes based on OpenDSSDirect updates, please add them here!

[PMeira]

For v0.9, there's a document with some notes and recommendations (the documentation as a whole was updated too): https://dss-extensions.org/OpenDSSDirect.py/updating_to_0.9.html