Add CatalogOptions to KeyValueClient, or add Datacenter to QueryOptions

[dtertman]

Sometimes it is necessary to query a Key/Value from another data center. The most visible use-case is a developer working locally on the laptop/desktop, but wanting to act like a QA or PROD server. Rather than running a local Consul instance, changing its datacenter, and redoing all of its joins, it would be much better to just tap into a consistent web API endpoint and use the existing WAN gossip.

The KeyValueClient currently doesn't support this, even though the underlying Consul API does. QueryOptions does not have a datacenter parameter, and CatalogOptions, which has a datacenter, isn't accepted by any of the KeyValueClient methods.

HealthClient, on the other hand, does support this method, through CatalogOptions.

[rickfast]

Hmmm surprised I never added that. Also surprised it hasn't come up as an issue. Fixed by ef3ca72