add keycloak package

Changes made to Helm chart:

• Added upstream chart from Code Centric
• Integrated with Istio to provide ingress
• Added CA and certificate overrides, defaulting to DoD CAs and *.bigbang.dev certs
• Added ability to load custom realm, defaulting to Platform One's
• Added ability to load custom registration configuration, defaulting to Platform One's
• Added Platform One customization for WildFly CLI
• Added support for clustering/HA
• Added network policy to limit port usage
• Added integration with Prometheus

Also made the following changes to Platform One's custom plugin for registration/auth in /development:

• Updated to support Keycloak 11.x