Sorting and filters for Manage A/B Tests page

Currently 'Manage A/B Tests' is a simple list with no sorting or filters. This will quickly become unwieldy as numerous tests are created over time.

1. Add 2 new columns to civicrm_mailing_abtest:
CREATED_ID - Contact who created the A/B test. FK to civicrm_contact.id
CREATED_DATE - Date and time that the A/B test was initially created

2. Add 2 columns to Manage A/B Test selector:
Created By - displays contact sort_name, link to view contact
Created Date

3. The following selector columns s/b sortable
Name
Created By
Created Date
Status

Default sort = CREATED_DATE descending

4. Add a form to filter the listings by:
Name
Created by
Created date
Status (Draft; Testing; Final)