Checkmk Werk 13263: Add (non-legacy) OAuth2 support (using TenantID, ClientID and ClientSecret) to check_mailboxes active check

ID: 13263 Title: Add (non-legacy) OAuth2 support (using TenantID, ClientID and ClientSecret) to check_mailboxes active check Component: Checks & agents Level: 1 Class: New feature Version: 2.2.0i1 Current check_mailboxes active check implementation used only legacy authentication for EWS mailboxes. This werk introduces client/tenant based authentication, while keeping legacy authentication still an option. Please note that previously, when using legacy authentication, you could use the login username as the email address for the mailbox you wanted to access. However, when using ClientID/TenantID, you now need to specify the email address separately. Please also note that this feature only applies to {{check_mailboxes}} for now.