Consider DirectoryScanner as alternative to copy resources using maven-filtering

[abelsromero]

I stumbled upon org.codehaus.plexus.util.DirectoryScanner (plexus-utils) which offers a way to select files using include and exclude patterns.
This will require some extra boilerplate code but will provide this advantages:

• Removing the use of org.apache.maven.model.Resource. Preventing confusion about the not-supported maven filtering options that now appear on some IDEs that offer maven's XML auto-completion.
• Improve build time since the logic will be simplified.
• Reduce the project dependencies since maven-filtering won't be necessary. That way users will have less to download.

[abelsromero]

Even when filtering is not a supported feature, this can break build. So I am thinking that if we do this one, we should release as major 3.0.0.

[abelsromero]

There seems to be an issue with latest maven 3.8.5 that would be mitigated with this change (https://issues.apache.org/jira/browse/MNG-7455?page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel&focusedCommentId=17521077#comment-17521077).