Send email util

[fredkingham]

Adds a util to send admins emails in a less verbose way.

• prefixes the subject with the opal brand name
• logs before and after

[fredkingham]

I've stuck this in cerner merges even though it can go in 108 as there will be an amendment to an existing PR (https://github.com/openhealthcare/elcid-rfh/pull/1429) that depends on it.