* MM-9849 Added tracking of which settings are set through environment variables
* Removed old version of viper
* Added forked version of viper
* Fixed unit tests
* Fixed more unit tests
* Removed copy from App.GetEnvironmentConfig
* Adding durafmt library and use it from enterprise global relay export
* Allow to specify different server host and server name on smtp connections
* Fixing utils/smtp tests
* Isolating configuration, sending emails and connection to SMTP.
* Building smtpAddress once
* Remove unnecesary errX variables
* Moving mail connection information to new data structure
* Added username to ChannelMemberHistory struct in anticipation of supporting GlobalRelay in Compliance Export
* Removed translation from debug output - this makes it complicated to use utils functions from tests in the enterprise repo
* Added an advanced email function that allows for greater control over message details. Updated MessageExport config to support GlobalRelay. Added attachment support to InBucket unit tests
* Moving templates in from enterprise to solve test issues
* Added export format to diagnostics
* Changed email attachment code to use FileBackend so that S3 storage is properly supported
