Bump kubernetes dependencies and apply required fixes

[mszostok]

Description

Changes proposed in this pull request:

• Bump dependencies
  • "sigs.k8s.io/controller-tools" to the newest version v0.2.4
  • sigs.k8s.io/controller-runtime" to the newest version v0.4.0
  • "k8s.io/api" to the version kubernetes-1.16.4
  • "k8s.io/apimachinery" to the version kubernetes-1.16.4
  • "k8s.io/client-go" to the version kubernetes-1.16.4
  • "k8s.io/code-generator" to the version kubernetes-1.17.0. Needs to be at least 1.17 to solve the issue with ignoring the genclient:nonNamespaced. More info here
  • github.com/kubernetes-sigs/service-catalog" to the newest version v0.3.0-beta.2
• Remove copied Rafter api from local sources and import it from external repo

Related issue(s)

• Upgrade api-machinery lib version for HelmBroker kyma-project/kyma#6644

[claassistantio]

All committers have signed the CLA.

[claassistantio]

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[mszostok]

/test pre-master-helm-broker-chart-test

[piotrmiskiewicz]

lgtm