Use of PluginBuilderFactory on AmqpAppender (Log4j2) (#1144)

* resolve #1142

Refactor @pluginfactory and use of @PluginBuilderFactory

Simplify subclasses implementation of AmqpAppender (Log4j2)

* Change Reference Documentation

Add Example for Log4j2 subclasses and static factor

* add test and fix logging.adoc

* fix LICENSE and logging.adoc

* fix missing rename file

* ConnectionFactory destroy() to avoid resources leaking

Author: Scip88