(POOLER-178) Target Stats for api & manager

Ensure that the correct stats are registered for the Manager and the api
respectively. E.g. all checkout counters are for the api only, whereas
clone times belong to the manager.

Also new ondemand functionality stats weren't registered, so add these
along with missing delete stats.

spec/integration/api/v1/poolreset.rb

@@ -37,7 +37,7 @@ describe Vmpooler::API::V1 do
 
     before(:each) do
       expect(app).to receive(:run!).once
-      app.execute(['api'], config, redis, metrics)
+      app.execute([:api], config, redis, metrics)
       app.settings.set :config, auth: false
       create_token('abcdefghijklmnopqrstuvwxyz012345', 'jdoe', current_time)
     end