Consider the right way to persist the user specified values and provide a way to allow clearing the values

[daxian-dbw]

Summary of the new feature / enhancement

What should we do with user's values when they run /refresh?
We need to consider the right way to persist the user specified values and provide a way to allow clearing the values.

It may be good to keep values around across chat sessions, so a user doesn't need to repeatedly input same values for like location, resource group name, sub id and etc. But on the other hand, user may really want to start clean.

Proposed technical implementation details (optional)

1. We may want to add flags to /refresh to control its behavior, like /refresh --all
2. We may want to support more fine-granular management over user values -- allow user to view, edit, and remove existing user values, and may be allow them to decide to persist into files, so they can be used in a different AIShell session.