[FEATURE] Clear cache function

[vars1ty]

Is your feature request related to a problem? Please describe.
Depends, users wants to sign in twice but can't because the Microsoft auth keeps them logged in, with no obvious way of logging out.

Describe the solution you'd like
A method to logout the active user (or clear the entire cache and everything with it) within MicrosoftAuthenticator.

[iSTeeWx]

You can modify the source code to include the content of commit 354715c, it will clear the cache each time you open a webview