title: Add tenants connectionstring and subdomain as a claim to the owin identity
body: <p>Is it secure to add the tenants subdomain and database connectionstring as a claim to the user <code>ClaimsIdentity</code> during login?</p>
  
  <p>In this way we won't need to access the master tenants database and we will only work with this <code>ClaimsIdentity</code>.</p>
  
  <p>Or can we create a custom <code>ClaimsIdentity</code> which contains a <code>Tenant</code> object that contains connection string and subdomain?</p>