[Feature] Add limited visibility to repos

[bestlinuxgamers]

Description

I would like to make repos available only to logged in users, as is already possible for organizations. This is currently possible with the REQUIRE_SIGNIN_VIEW setting, but I don't want this to affect all repos.

What to implement

A good solution would be to add a "Limited" visibility (like for organizations).

[xeruf]

Yes I agree, I don't want to add all our team members who have to log in via SSO anyways to an organization, this would be very handy!