Closes #57804

This PR adds an option to GitLab code host connections called markInternalReposAsPublic, which sets the visibility of all internal repos added by this code host connection to true, and an option to the GitLab auth provider called syncInternalRepoPermissions. syncInternalRepoPermissions are true by default, and can be set to false to optimise systems where markInternalReposAsPublic is set to true.

Test plan

Unit tests updated. Set up and tested locally as well.

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    Backport 2ea61e5 from Add options to configure internal repo handling for GitLab #57858

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