prevent sending notification for SCC no registration to non-admin users and if feature flag is not enabled

[aalves08]

Summary

Fixes #15807

Occurred changes and/or fixed issues

• prevent sending notification for SCC no registration to non-admin users and if feature flag is not enabled

Technical notes summary

• Followed same gating as https://github.com/rancher/dashboard/blob/master/pkg/rancher-prime/config/navigation.ts#L14-L15
• For now we can't prevent registering routes from extensions, as per Tech debt: Gate the addRoutes for extensions to follow the same conditions as configureType/virtualType #15645, so next best thing is to prevent displaying links to "protected" areas

Areas or cases that should be tested

• With a Rancher Prime version, not registered with SCC, do a login:

• Admin: should see notification that Rancher isn't registered

• Standard user: should NOT see notification that Rancher isn't registered

• User Base: should NOT see notification that Rancher isn't registered

IMPORTANT NOTE: If while Admin you're not seeing SCC registration entry in the settings area, make sure that feature flag rancher-scc-registration-extension is enabled

Areas which could experience regressions

Screenshot/Video

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes
• The PR has been reviewed in terms of Accessibility
• The PR has considered, and if applicable tested with, the three Global Roles Admin, Standard User and User Base