A Message represents a MessageDestination independent way to send a message to a platform.
However - not every destination will support every type of formatting, or may have length / size
restrictions - so be aware of this. Destinations should do their best to receive the message, even if they
have to ignore formatting to do so.
The level / severity of the Message. This can be thought of as the log level.
This is used in conjunction to Component to indicate how a message should be
routed.