Unifying NFD operator and operand repositories

**What would you like to be added**:
Currently NFD operator code and NFD operand code are residing in 2 different independent repositories. We can unify those repositories into one repository that will include both operator and operand code and deployments. It will also means that any PR to the unified repository will be verified via operator deployment and execution.

**Why is this needed**:
1. Having 2 different repos requires synchronization for major commits between operand and operator, in order to support new features in the operator.
2. Currently some of the APIs are defined and reside in the operand repository, which requires synchronizing them into the operator repository and adding their deployment to the operator code.
3. Since most of the development is done on the operand code, the operator code is neglected, and frequently becomes broke due to reasons 1 and 2
4. Unifying repos will remove the duplication of the APIs mention in 2.
5. We can still support deployment of operand alone, if this will be required by the users.
6. Unifying will allow easier deployment of the NFD via operator, which is more conventional K8s way
7. Unifying repos will allow unified release for both operator and operand
8. It will also allow easier upgrade process, since the operand image will be more accessible to the operator

Start by mapping the separate NFD operator and operand repositories, their APIs, deployment paths, and release process; the issue names no files or tests. Define the integration scope and verify that the unified repository can deploy and execute through the operator, support operand-only deployment if required, and provide a unified upgrade and release path.

Written by the indexing model from the issue text.