Support console logins like aws-vault

[ziegeer]

aws-mfa is great thank you but is missing one feature that'd allow me to rely solely on it, the ability to get a federated, short-term authenticated console url/login. In the similar tool aws-vault that happens with aws-vault login <profile name> and it opens the AWS console for that account. Without that, cli access works great but there's no way to get console access via aws-mfa alone.