Deprecate LOGGED_APPLICATION_NAME log property in favor of APPLICATION_NAME with the verbatim value

[philwebb]

In order to support #5479 we need to access application.name. Currently we only store the value as LOGGED_APPLICATION_NAME and it is formatted inside square brackets with a trailing space. We should be able to replace the stored formatting with a customer converter, then store application.name directly so it can be used by structured logging.

[philwebb]

As an added bonus, we can then also change APPLICATION_GROUP and remove the ApplicationGroupFormatter.