(#9241) Make the reload action of the server models work

Without this patch, we could not call the reload method
of a server model instance.  This is because the Fog library
would try to call the get method using the existing identity
(instance_uuid) as the key.

This patch implements the get method by instantiating a new
model instance from a set of attributes obtained from the
vmware managed object instance.

The logic reflects that inside of the backspace servers
collection implementation.

As a side effect of this patch we also get wait_for.
For example:

  server = Fog::Compute[:vsphere].servers.last
  server.start
  server.wait_for { ipaddress }

lib/fog/vsphere/models/compute/servers.rb

@@ -19,11 +19,11 @@ module Fog
           load(vm_attributes)
         end
 
-        def get(server_id)
-          raise NotImplementedError
-          # FIXME: (TODO) Make a raw API call
-          # Massage the data into an attribute hash
-          # Pass the attribute hash to new() to create a new instance of the model.
+        def get(instance_uuid)
+          vm_mob = connection.find_all_by_instance_uuid(instance_uuid).first
+          if server_attributes = model.attribute_hash_from_mob(vm_mob)
+            new(server_attributes)
+          end
         rescue Fog::Compute::Vsphere::NotFound
           nil
         end