Redesign Package Registry project setting

What does this MR do and why?

In !82808 (merged), a new visibility setting for the Package Registry was added to the project settings - behind the package_registry_access_level feature flag. In the meantime, there was a discussion about the UI resulting in a new UI suggestion. This MR redesigns the Package Registry setting within the project settings - still behind the package_registry_access_level feature flag.

• UI suggestion: #329253 (comment 1168299354)
• Implementation plan: #329253 (comment 907634930)

🛠 with ❤ at Siemens

/cc @bufferoverflow

Screenshots or screen recordings

Before (with enabled feature flag)	After (with enabled feature flag)
private project: internal project: public project:	private/internal project: public project:

How to set up and validate locally

1. Enable the feature flag

   Feature.enable(:package_registry_access_level)

2. In a project, go to Settings > General > Visibility, project features, permissions.

MR acceptance checklist

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