SAMLUtils: leave bootstrapping to upper layers

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
api: add method to pass on api authenticators to cmd classes

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
saml: Implement logic to check response against X509 keys

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>