Fix Windows platform implementation of sessions command

[Acters]

Description of Changes

This fixes the Windows implementation of enumerating a list of users.
Also, added extra type checks for edge cases to prevent confusing errors, and will now raise a ModuleFailed error incase users variable is not a dict or list of users.

Major Changes Implemented:

• Commented the hard coded users = users[0] as it caused a type error and it would only allow the very first user in list to display when using the sessions command. This is commented because a future feature can allow picking which user in list to grab info from, instead of all the sessions.
• Added some basic type checks to make code more robust to possible edge cases. A dict will now be treated like a dict, and a list will always be enumerated. If users variable is neither a dict or list, then it will raise a ModuleFailed error.

Pre-Merge Tasks

• [ + ] Formatted all modified files w/ python-black
• [ + ] Sorted imports for modified files w/ isort
• [ + ] Ran flake8 on repo, and fixed any new problems w/ modified files
• [ + ] Ran pytest test cases
• [ + ] Added brief summary of updates to CHANGELOG (under [Unreleased])