Python style and best practices

[mjd3]

• Use python properties instead of get_x functions
  • We have a lot of functions in aws.py that use get_x (and corresponding calls to y.get_x()) for attributes that should be properties of the class. These should be changed to use the @property decorator and @x.setter (if not readonly).
• All internal variables should be prefixed with _ (as in, self._x).
• Abstract base classes should have separate files from their derived classes (e.g., AWS implementation of CloudInstance)
• Replace string concatenations using + with f-strings
• Replace print with logging where possible

[SimeonOA]

Check for Python Style guide/ checker