Support for BitBucket HTTPS Token due to SSO/SAML authentication restrictions

## Description

We need a way to migrate from BitBucket with SAML Authentication enabled. We believe this can be solved by supporting BitBucket HTTPS token which `gh bb2sgh` doesn't support.

> (Unauthorized): {"errors":[{"context":null,"message":"Authentication failed. Please check your credentials and try again.","exceptionName":"com.resolution.atlasplugins.samlsso.bitbucket.userauth.OnlySAMLAuthenticationAllowedException"}]}