[SDK-4011] Add API2 Factor Management Endpoints

[adamjmcgrath]

Changes

Method	Endpoint	Description
GET	/api/v2/users/{user}/authentication-methods	Gets a list of authentication methods
GET	/api/v2/users/{user}/authentication-methods/{authentication_method_id}	Gets an authentication method by ID.
POST	/api/v2/users/{id}/authentication-methods	Creates an authentication method for a given user.
PUT	/api/v2/users/{user}/authentication-methods	Updates all authentication methods for a user by replacing them with the given ones.
PATCH	/api/v2/users/{user}/authentication-methods/{authentication_method_id}	Updates an authentication method.
DELETE	/api/v2/users/{user}/authentication-methods	Deletes all authentication methods for the given user.
DELETE	/api/v2/users/{user}/authentication-methods/{authentication_method_id}	Deletes an authentication method by ID