fix: report list search by created_by

[graceguo-supercat]

SUMMARY

This PR is to fix the issue when search by created_by in report/alert list.
Steps to reproduce (see issue##17162)

1. open alert/report list
2. In CREATED BY, search for a username, for example "Grace".

3. It will generate a request to /related/ endpoint: Request URL: https://superset.d.musta.ch/api/v1/report/related/created_by?q=(filter:grace,page:0,page_size:100)
4. But for report schedule, it has owners in related_field_filters, not created_by. This mis-match cause filter didn't take any effect.

The proposed fix is to use created_by in the related_field_filters.

TESTING INSTRUCTIONS

CI and manual test