Allow 'delta' node recovery mode to be selected for analytics nodes

In Vulcan, analytics will only do 'delta' recovery.  While topology service implementation does not seem to ever indicate 'delta' as the recovery mode, it would be friendly to allow users of the REST api & cli to enable delta recovery mode on analytics nodes.

In the Alice timeframe, hopefully we can get the delta recovery type to be sent through the topology-aware service api when selected as well, but that is tracked in a different issue (MB-28140)