User ID Attribute Name Variants: user_id_attrs

[drfho]

hi @zmsdev ,
for flexible usage of the SSO-Plugin we need

1. to allow more name variants for user_id or login_name, I recommend to add a new attribute "user_id_attrs" as a comma-separated string, see image.
2. The None-setting might be redundant?
   self.doAddUser(None, None)
3. function authenticateCredentials() might use another function to process the get_user_id_attrs-filed an return a list
4. an idea is needed to abstract special requirements like: username = username.split('@')[0]. Maybe a custom preprocessor py script of the zope object.
5. to get roles from the json payload the SSO-plugn should allow role-extraction, too, like

[zmsdev]

ad 2.)
doAddUser(None,None) is just used to refresh users (login and password must be passed).