Add Hidden Auto Squad Types

[Bluedagger21]

This is a request to add a new type or toggleable option to Auto Squads that will hide the Squad from everyone except members, moderators and superusers.

Use Case for Auto-Hidden: We want to track who can build capital ships and parts in our alliance automatically, but we don't want to share that information to everyone who auths with SeAT, only the members of the Squad (if the Squad is not classified).

Use Case for Auto (not Hidden): A pseudo-certification (related to #661) for excellent scanning skills. This can be seen to create a desire to reach membership to a squad.

[nuclear4547]

I'd like to have auto-hidden squads like that, too.