Extract shared mailing report columns and logic into CRM_Report_Form_Mailing_Base

[colemanw]

Overview

Reduces copy/paste code redundancy in mailing report forms.

Before

Mailing report forms were built with copy & paste.

After

Less so.

Technical Details

Extract duplicated mailing report columns, filters, and SQL logic from CiviMail report form classes (Detail, Bounce, Clicks, Opened) into an abstract base class CRM_Report_Form_Mailing_Base.

[civibot]

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[mlutfy]

Merging based on a quick r-run (but demo site does not have mailing data), some code review, and my appreciation for the reduction of copy-pasted code.

[colemanw]

Thanks @mlutfy