Allow email view modes to be overridden

Problem/Motivation

This is a great module. We would like to be able to send more than one notification per message. So the message is recording an event, and we would like to send notifications of the event to multiple recipients, and we would like the email messages to the different recipients to be different. We would not like to create multiple messages to handle the different notifications, because we want to preserve the idea that there is one and only one message to record the event.

Proposed resolution

We would like to override the subject and body view modes via the $options parameter that gets passed into the notifier.

The override would then happen in MessageNotifierBase.

This doesn't require much code at all. I don't know if this is a feature you want to add to the module or what consequences could occur from the change.