Ensure uniqueness and validity of generated names and labels

[pleshakov]

Problem:

Provisioner could generate an invalid name or a label for NKG static mode deployment. As a result, the provisioner would fail with an error like below:

{“level”:“info”,“ts”:“2023-06-05T17:26:04Z”,“logger”:“eventLoop”,“msg”:“added an event to the next batch”,“type”:“*events.UpsertEvent”,“total”:1}
panic: failed to create deployment: Deployment.apps “nginx-gateway-gateway-conformance-infra-same-namespace-with-http-listener-on-8080" is invalid: [spec.selector.matchLabels: Invalid value: “nginx-gateway-gateway-conformance-infra-same-namespace-with-http-listener-on-8080”: must be no more than 63 characters, spec.selector: Invalid value: v1.LabelSelector{MatchLabels:map[string]string{“app”:“nginx-gateway-gateway-conformance-infra-same-namespace-with-http-listener-on-8080”}, MatchExpressions:[]v1.LabelSelectorRequirement(nil)}: invalid label selector]

Solution:

Provisioner will use the following format for names and labels of Deployments:
nginx-gateway-<number>, where the number if an interger >= 1. For every new Gateway resource, the provisioner will increment the number by one.

This approach will break if the provisioner is restarted, but we don't support provisioner for production yet, so it is acceptable.

Note: correlation between a Gateway resource and the corresponding Deployment can be found in the provisioner log. For example:

{"level":"info","ts":"2023-06-05T21:23:33Z","logger":"eventHandler","msg":"Created deployment","deployment":{"name":"nginx-gateway-1","namespace":"nginx-gateway"},"gateway":{"name":"same-namespace","namespace":"gateway-conformance-infra"}}

This PR will unblock #713 (comment)

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• I have read the CONTRIBUTING doc
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