Introduce `NifiCluster` v2alpha1

[mh013370]

Is your feature request related to a problem?

No

Describe the solution you'd like to see

Use the operator-sdk to introduce:

apiVersion: nifi.konpyutaika.com/v2alpha1
kind: NifiCluster

This new version will become the hub() for the NifiCluster CRD, so implement the appropriate CRD conversions from v1alpha1 and v1 into v2alpha1. This means that the NifiCluster controller will handle only v2alpha1 version objects.

Describe alternatives you've considered

No response

Additional context

No response