Description of problem: upstream docs https://github.com/openshift/oadp-operator/blob/master/docs/design/datamover.md refer wrong CRs which do not exist on practice.

It's important to keep this info up to date as it will be used as reference by Doc team for downstream documentation (see https://issues.redhat.com/browse/OADP-566).

Version-Release number of selected component (if applicable): OADP 1.1

Actual results:  Upstream docs refer CRs such as DataMoverClass, DataMoverBackup and DataMoverRestore that do not exist in practice. 

Expected results: upstream design should reflect the actual flow and custom resources.