Refine dmn-drools-*-metrics

Currently, dmn-drools-quarkus-metrics and dmn-drools-springboot-metrics have the following minor issues
1) issue `mvn clean install -DskipTests` inside ` dmn-drools-quarkus-metrics` does not copy dashboards, because in quarkus they are generated after prepare-package
2) the build works only invoking the `install` phase, needlessly forcing the user to copy the artifact in the .m2 directory

Scope of this PR is to
1) define a common, working phase for copy-resources for both quarkus and springboot
2) allow user to successfully runt the example without `install` the artifact in the .m2 repo