Update file backend password prompt, add option to clear the entire Granted cache

[meyerjrr]

What changed?

Updates the function used for retrieving the file backend password. Adds a --all flag to the granted cache clear command to clear all the credentials in the backend

Why?

Adds an easier way to access the file backend. Adds an easer method of clearing the entire cache.

How did you test it?

assuming a role with my backend as file. Was not prompted for a password

Ran granted cache clear --all and it cleared out all the credentials for a storage type

Potential risks

Is patch release candidate?

Link to relevant docs PRs