net/keycloak: update to 23.0.6

• Update to 23.0.6
• Add keycloak user and group
• Add pkg-message
• Add support for development(start-dev) and production (start) mode at rc script
• Export JAVA_HOME from rc script
• Add keycloak build function into rc script

PR: 275658 276859
Approved by: maintainer timeout (2 weeks)