Add ability to show cc and bcc recipients if present, and not error on missing To recipient

[compwron]

Overview

Add ability to show bcc recipients if present, and not error on missing To recipient

Notes

This codebase uses https://www.npmjs.com/package/mailparser and the docs there imply to me that this is possible.

Command to run the tests on my local, thanks to denis90: NODE_OPTIONS="$NODE_OPTIONS --experimental-vm-modules" npm test

Refs: LM-zxy

[compwron]

@denis90 or @veelenga can you approve my PR GHA CI run and review/stamp? (Sorry to hurry you, I am just enthusiastic...) If you expect that it will take a few days or a week to get to this, I will just release a temporary npm fork build for my team :)

[denis90]

LGTM