Fix visibility of forked public repos from private orgs

[CirnoT]

Ensure that public repos of private orgs (so called internal repos, visible only to members of organization) are set as private when forked.

Most likely kind/security

[CirnoT]

Needs additional logic for when org visibility is changed.
Done

[CirnoT]

Added logic to update forks visibility when org visibility has changed.

[lafriks]

For initial yes but I don't think it is good idea to update visibility on main repository visibility change.

[CirnoT]

For initial yes but I don't think it is good idea to update visibility on main repository visibility change.

I don't understand. Forked repositories always follow parent, the visibility can not be changed on fork - ever. This PR only fixes it so that organization visibility is also included. This is a security fix as public repository of private organization is visible only to organization members, but upon forking it's visible to everyone. In addition forking can not be disabled so organization owner can never prevent leakage of public repos in a private org.

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That being said I agree that forks of public repo should not follow parent when it goes into private mode; in particular this should be solved by decoupling forks from parent (turning them into normal repositories) once parent becomes private. But that is out of the scope for this PR.

[CirnoT]

Ready for merge, addressed @guillep2k questions here: #11717 (comment)

[zeripath]

make lg-tm work

[techknowlogick]

ping LG-TM