Add ability to view currently loaded variables and their values

[cbruno10]

Is your feature request related to a problem? Please describe.
I'm not sure what variables are loaded when running queries or checks, or what their values are.

Describe the solution you'd like
It would be helpful if I could view variables and their values, either in an interactive steampipe query session, or in a non-interactive session with a specific command.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.