Refactor Email module to use `Email` resources and JIT all template processing

[hellopablo]

When there are many items in the email archive the admin email archives are chronically slow.

[hellopablo]

The slow part is the formatObject call which is executed in the getAll method of Emailer. A larger refactor of the emailer should really be completed so that all emails are instances of Email resources and all processing (e.g. rendering templates) is done when needed/accessed rather than ahead of time.