NXP-10839 register xa datasource in nuxeo container in tomcat environment

Conflicts:
	nuxeo-distribution-resources/src/main/resources/templates-tomcat/common-base/nxserver/config/default-repository-config.xml.nxftl
NXP-10903 xa datasource pool plug in storage (with backward compatibility)
NXP-10926 mvcc enabled in h2

Conflicts:
	nuxeo-distribution-resources/src/main/resources/templates-jboss/default/nuxeo.defaults
	nuxeo-distribution-resources/src/main/resources/templates-tomcat/default/nuxeo.defaults