[Ref] Move rule to email trait

[eileenmcnaughton]

Overview

[Ref] Move rule to email trait

This is part of dis-establishing EmailCommon - the function is not called from elsewhere

UPDATE - I found a place in 'universe' - so I deprecated instead of removing

Before

Function on deprecated class, only used from the trait

After

Function on the trait

Technical Details

A universe search shows it is not used other than here

Comments

[civibot]

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