[Updates] Toast notification for new updates: Add setting

[htcfreek]

This is the update notification setting part from #30606.

Summary of the Pull Request

This PR adds a setting to manage action center notifications (including a new policy).

PR Checklist

• [x] Touches: #25717
• [x] Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• [ ] Tests: Added/updated and all pass
• [x] Localization: All end user facing strings can be localized
• [ ] Dev docs: Added/updated
• [ ] New binaries: Added on the required places
  • [ ] JSON for signing for new binaries
  • [ ] WXS for installer for new binaries and localization folder
  • [ ] YML for CI pipeline for new test projects
  • [ ] YML for signed pipeline
• [ ] Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

• Tested the behavior of the settings ui.
• I can't test the behavior of the updater code. This must be done by the reviewers.