Enable support for redis clustering

Summary
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Enable support for Redis in database clusters.

Motivation
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Database clustering in Horizon is currently enabled for datastores that Trove can provision clusters for such as Mongodb and Vertica. Support for provisioning Redis clusters is now available in Trove so the Redis datastore clustering in Horizon should be enabled.

UX
==

Enabling Redis clustering will simply reuse the existing Launch Cluster dialog. The Redis datastore will be in the datastore pulldown. When the user selects Redis the Launch Cluster dialog fields will dynamically change to display the default Launch Cluster fields.

There will be a new detail overview panel with Redis cluster specific information.

There are no additional actions to be added at this point for the Redis cluster.

Outside Dependencies
==================

Uses existing Trove APIs

Requirements Update Required
========================
N/A

Doc Impact
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No changes for Horizon documentation. Trove documentation will need to be updated.