Use templates for email body formatting for admin emails

[gnott]

Emerging as an observation on PR #1006 where simple email body formatting was changed to use a template, there are other more lengthy emails that are not formatting with templates, including,

"... in PackagePoA, PublishFinalPOA, PubmedArticleDeposit, PubRouterDeposit, and a little in PublicationEmail."

There is also some question about whether these other emails could be expressed as simple string replacement templates or,

"... would possibly be better as jinja2 templates, but it may be possible to just use string replace templates."

@giorgiosironi commented,

"Do the templates contain conditionals or loops? That would be the Godzilla threshold that would call for Jinja or a similar full templating language."

This issue is a placeholder for further investigation and discussion, possibly leading to implementation of converting these email body formatting into template driven logic.

• Do we want to convert the remaining email body logic functions into templates?
• In terms of priority, when to do this?
• Depending on the above, collect and analyse the existing emailing functions, look for commonalities and how template(s) could be used to satisfy the situations
• Create the template(s)
• Refactor programming logic, where possible, to use the template-based solution