Improve a way how operator handle CheCluster CR

[tolusha]

Is your enhancement related to a problem? Please describe

There several areas where we can improve how operator handles CheCluster CR.
Some changes aren't possible until we support OCP 3.11 and use corresponding apiextensions.k8s.io/v1beta1 API.

Describe the solution you'd like

• Operator must not update CR spec from the code. It is only allowed to update status fields.
• Use kubebuilder:default to set default values for fields
• Use MutatingWebhook to set record level defaults
• Use kubebuilder:validation to set field validation
• Use ValidatingWebhook for record level validation

https://book.kubebuilder.io/reference/markers/crd-validation.html
https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/
https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.22/#mutatingwebhookconfiguration-v1-admissionregistration-k8s-io
https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.22/#validatingwebhookconfiguration-v1-admissionregistration-k8s-io

Describe alternatives you've considered

No response

Additional context

No response

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