Describes the procedure for upgrading the major version of the operator and FEP container.

A major version upgrade of a FEP builds a new major version of the FEP in the same Namespace as the previous major version of the FEP. At this time, by defining the "spec.fepChildCrVal.upgrade" field in FEPClusterCR, the operator creates the upgrade execution container. The upgrade execution container uses the previous version of FEP Cluster specified in "spec.fepChildCrVal.upgrade.sourceCluster" as the data source FEPCluster and migrates the data to the newly created FEPCluster.