External Users will not inherit project limits and it's not clear in the UI

I was helping a customer debug their users not getting the appropriate project limit here: https://gitlab.zendesk.com/agent/tickets/72950

and that is when we realized that external users will not inherit project limits:

https://gitlab.com/gitlab-org/gitlab-ce/blob/v9.0.0/app/models/user.rb#L974-979

This issue is slightly related to https://gitlab.com/gitlab-org/gitlab-ce/issues/30725

But essentially, it would be great in the UI if it was clear that project limit was being set/overriden by the external flag. The user suggested a blue ? next to the zero project limit if the user was external linking to documentation or a tooltip explaining why.