[OCP] Add more flexibility to the standard PAM images

In order to access to the PAM deep customization and tuning, we need more customization handles:

• Define users/group in the underlying EAP
• Add custom system properties
• Add files in the kie-server.war and business-central.war
• Add / override files in ROOT.war/WEB-INF/classes/ (for BC and KS)
• Configure the smtp server,
• change the maven settings: ~/.m2/settings.xml
• Update the the EAP logging configuration
• ssh configuration: Configure the ssh directory, by default it’s in the <EAP>/bin/.security, but you can update it with the following system property org.uberfire.nio.git.ssh.cert.dir