esx: Support folders in the path of vpx:// connection URIs

esx: Support folders in the path of vpx:// connection URIs

Allow the datacenter and compute resource parts of the path
to be prefixed with folders. Therefore, the way the path is
parsed has changed. Before, it was split in 2 or 3 items and
the items' meanings were determined by their positions. Now
the path can have 2 or more items and the the vCenter server
is asked whether a folder, datacenter of compute resource
with the specified name exists at the current hierarchy level.

Before the datacenter and compute resource lookup automatically
traversed folders during lookup. This is logic got removed
and folders have to be specified explicitly.

The proper datacenter path including folders is now used when
accessing a datastore over HTTPS. This makes virsh dumpxml
and define work for datacenters in folders.

https://bugzilla.redhat.com/show_bug.cgi?id=732676