[cmdpal][aot] Make app extension become AOT compatible

[moooyo]

Summary of the Pull Request

• Make app extension become AOT compatible
• As a demo to share how to remove/change the DllImport to LibraryImport. DLLImport is not AOT compatible.
• It works in my x64 laptop, I'm not sure if it works in arm.

PR Checklist

• Closes: #xxx
• 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
• 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