Duplicate EmailCommon::buildQuickForm onto the trait

[eileenmcnaughton]

Overview

Copy EmailCommon::buildQuickForm onto the new trait we are using instead of the static class for shared email form functionality

I have duplicated this code rather than moving it in case any non-core code calls it. We can remove in a bit

Before

buildForm is on the static class - it references many form attributes that are inconsistently defined

After

buildForm is on the trait. The old code remains in the static function with a deprecation notice in case anyone is accessing it in an unsupported way

Technical Details

Comments

[civibot]

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[demeritcowboy]

• General standards
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    • There's a couple === that snuck in there but otherwise is the same.
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[eileenmcnaughton]

thanks @demeritcowboy