introduce a way to restrict authorization methods via configuration
dmx-sign-up has a config parameters that currently influences which authorization methods are available (and in what order). This option however only has an effect on the web ui that the plugin renders itself. Additionally the option is completely cosmetic because the platform itself still allows login with whatever available authorization method.
ACs:
- configure allowed authorization methods via property dmx.security.restrict_auth_methods
- the property should contain comma-separated a list of allowed authorization methods
- the platform should only allow logins with the mentioned authorization methods
- the function List getAuthorizationMethods() should only return the authorization methods that are left after having applied the filter list from the configuration option
- the order of the items in the filter list should be reflected in the getAuthorizationMethods() function