Add allowedDomains to Microsoft connector.

[maordavidov]

The existing Microsoft connector does not support allowedDomains like Google connector or other connectors allows.

Overview

The existing Microsoft connector does not support allowedDomains like Google connector or other connectors.

What this PR does / why we need it

Microsoft connector supports too-open or too-close scenarios (either all organizations/schools or all users or on the other hand only one specific tenant). Our organization needs to approve a list of domains like Google connector supports. This PR adds the logic to verify the specific domain is approved to receive a token from Dex.

Special notes for your reviewer