Add inventory folder support to vic-machine and VCH

[hickeng]

Add folder and naming pattern options to vic-machine design doc and implementation.

Various customers use folder and naming conventions as organisation mechanisms within VC, and if we're going to allow tight integration we need to support continued usage of those models.

There are two variants of folders that we must concern ourselves with:

1. datastore folders - only relevant on non-vSAN datastores
2. datacenter folders - only relevant on vCenter

(1) is expected to be addressed via container-store options to vic-machine.

This issue addresses (2), and it's expected that be done via a name pattern that includes a datacenter folder path element.

[karthik-narayan]

@andrewtchin @emlin I assume that this is the issue we hit with the customer. Could you confirm?

Also @hickeng the customer was using folders in VC to organize their switches. Besides datastores and datacenters, we might also need to account for folders in networking.

[emlin]

@hickeng @karthik-narayan This customer also has network folder
And also one question for the datastore folders. As George mentioned, this issue should be solved in container-datastore, don't we want to have folder support for image datastore and volume datastore?
This customer has pretty everything under folder.

As we already had hierarchy structure to configure datastore path in the parameter for image datastore, volume datastore, I'm wondering if together with folder hierarchy, we'll need more complicated validation.

[karthik-narayan]

I'll let you figure out the implementation details, but this is a use case that I've hit more than once and is a very common one. Asking customers to move objects out of the folder to get VIC working is a non-starter and we should get to this at the earliest.

[stuclem]

Already in the release notes, so removing the kind/note tag.