UI : Provide option whether to delete propagated classification on entity delete during add classification

By default, when an entity is deleted - its associated classifications which have been propagated to downstream entities will be retained.

This JIRA provides a boolean option when adding a new classification to an entity - "Remove Propagations on Entity Delete"

When this flag is set to :

TRUE - Propagated classifications are removed during entity delete

FALSE - Propagated classifications are retained during entity delete