Provide feedback indicating Okta+Duo MFA is pending

[sparr]

Is your feature request related to a problem? Please describe.
I was confused and frustrated when my vault login -method=okta appeared to be stuck, but it was actually waiting for me to approve a Duo push on my mobile device.

Describe the solution you'd like
Some output in the console indicating the state of the auth request.

Describe alternatives you've considered
Turning on audible notifications for Duo on my mobile device.

Explain any additional use-cases

Additional context

[jeffsanicola]

This was also affecting Okta + Okta MFA. This would be a good feature for all the supported MFA methods if not already implemented.

[sparr]

It occurs to me that vault might not even know that there's MFA happening. It could just think Okta is taking forever to respond to the password entry.

[erickufrin-okta]

We are looking for this feature as well. This is probably our #2 reason for Vault logon failure.

[hghaf099]

@sparr Thank you for filing this request. We will discuss this with our product and decide internally.