Allow non-interactive way to delete the operator using kubectl plugin

[thomasjm]

Is your feature request related to a problem? Please describe.

This is the same as #710, but for the operator itself instead of tenants.

Currently kubectl minio delete asks for confirmation; implement a flag --force to avoid interactive behavior.

Describe the solution you'd like

kubectl minio delete --force

Describe alternatives you've considered
Skip deleting my operator in tests and just let it be destroyed when the cluster is removed.

Additional context
For scripts, tests, or other non-interactive use.

[cniackz]

I was reviewing this change to explain or help Abdul with this task and found that the solution can be found here:
https://github.com/minio/operator/pull/711/files

[cniackz]

Similar code will apply not just for the tenant but for the Operator as well:

[cniackz]

Now to test the code change, we can look at Pedro's notes at: #1612