Enhance Dependent Resources sample / impl to how to manage resource with multiple owners

[csviri]

Note that there is now an issue that when one of the CR's is deleted it actually not cleanup it's own data in MultiOwnerDependentTriggeringIT.

One solution is to not have the DR garbage collected, and override the delete to remove the data and owner reference label (it's label if not GC-d). But that we have to customize also the owber label key naming.

Note sure how or if we want to support this use case more explicitly since it is quite rare, so for now will just show in the test how to do it with current setup.

See discussion here:
#3122
#3123