What does this PR do

This commit fixes the search issue introduced by commit. We have no idea why the tauri command get_app_search_source won't be invoked after that commit on Windows.

This commit resolves the issue by moving the extension init logic to the Rust side.

Also, update the querysource logs in quey_coco_fusion(), the old one won't say anything if the querysource list is empty, the new one will tell us that.

Rationale for this change

Standards checklist

• The PR title is descriptive
• The commit messages are semantic
• Necessary tests are added
• Updated the release notes
• Necessary documents have been added if this is a new feature
• Performance tests checked, no obvious performance degradation