Add warning next to public projects shared with a private group

What does this MR do and why?

Related to #361621

Per https://gitlab.com/gitlab-org/gitlab/-/issues/361621#note_999855445 this is okay to be handled in the gitlab-org/gitlab repository.

In GitLab it is possible to share a project with a group. Though sharing a public or internal project with a private group has some consequences that will be documented in !91379 (merged)

This MR adds a popover warning next to public projects that warns the user of these consequences and links to the docs for more information.

Screenshots or screen recordings

Desktop

Before	After

Mobile

Before	After

How to set up and validate locally

1. Create a private group
2. Create a public project
3. Navigate to the public project -> Project information -> Members
4. Click Invite a group in the upper right corner
5. Find the private group you made in step 1 and select it
6. Navigate to the private group and click the Shared projects tab

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.