[feat] Make use of known-to-be-existent stuff on Openshift

[markusthoemmes]

Describe the solution you'd like
I'd love if I wouldn't have to deal with the fact that we're building images when running on Openshift at all. Wouldn't it be cool if one could just do kn faas deploy on an Openshift cluster without additional setup (i.e. dockerhub accounts etc.).

We discussed briefly how it's non trivial to talk to the Openshift internal-registry, but maybe we can salvage Openshift builds (and their binary input feature) to build images on the cluster and into the registry on the fly.

[lance]

@markusthoemmes I think this should be covered by our On Cluster Builds FT - potentially by TP.

[omerbensaadon]

Checking on this, can this issue be closed?

[zroubalik]

@omerbensaadon this is still not resolved

[lance]

Closing as a duplicate of #620

[nainaz]

related to #620