[DO NOT MERGE] Openwhisk2

[francescotimperioss]

This PR contributes the minimal required changes to execute Openserverless against Openwhisk2 images generated via the openserverless-build.
It contributes:

1. Controller and Invoker based on latest Openwhisk source code, including a patch required to make the invoker working without the scheduler. The images are pushed on the official apache ops docker hub account
2. A fix to take into account the configured invoker and controller images (in the wsk/controller or in the operator image env variable)
3. The necessary changes to configure the OW2 controller and invoker to be able to work without the scheduler.

Do not forget that OW2 by default uses the scheduler, which is not currently configured by the ops operator.

This PR is meat to show the relevant changes needed to use the latest OW2 based images.