Make organization required for smartcard login logic

What does this MR do and why?

As part of cells 1.0, we need to ensure that a Namespace does have an organization assigned. We are now relying on database 'default 1' value but we need to make this explicit.

This MR will assign an explicit organization to the namespace of users that are created using SmartCard controller.

Since Smart card authentication is only available on Self-managed, we can assign the default organization to the namespace of these users. This is achieved by adding organization as an additional required argument to the Gitlab::Auth::Smartcard::Certificate and Gitlab::Auth::Smartcard::LdapCertificate classes

Related to #443494 (closed)

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