Add properties to phoenix hbase-site.xml #288

For a better and cleaner data handling I would like to see the following properties added to the /stackable/phoenix/bin/hbase-site.xml as well as the discovery configmap of hbase.
The phoenix hbase-site.xml can not be modified with configOverrides. This is a prerequisite for the hbase-phoenix-trino demo. During my tests phoenix did not work well with the default namespace. These properties helped stabilizing it.

<property>
        <name>phoenix.schema.isNamespaceMappingEnabled</name>
        <value>true</value>
      </property>
      <property>
        <name>phoenix.schema.mapSystemTablesToNamespace</name>
        <value>true</value>
      </property>