Stop reconciliation on empty CRD modifications

[prune998]

This code compares cached CRD to the new MODIFICATION event and skip reconciling the CRD if the change is trivial.

Here's what changes in the CRD in a GKE cluster where the addon-manager keeps patching some CRDs:

argocd-application-controller-0 application-controller watchEvents mismatch for CRD {apiextensions.k8s.io CustomResourceDefinition  gcpbackendpolicies.networking.gke.io} (-want +got):
argocd-application-controller-0 application-controller   v1.CustomResourceDefinition{
argocd-application-controller-0 application-controller   	TypeMeta: {Kind: "CustomResourceDefinition", APIVersion: "apiextensions.k8s.io/v1"},
argocd-application-controller-0 application-controller   	ObjectMeta: v1.ObjectMeta{
argocd-application-controller-0 application-controller   		... // 3 identical fields
argocd-application-controller-0 application-controller   		SelfLink:          "",
argocd-application-controller-0 application-controller   		UID:               "8a9b77ed-241f-43a6-8125-f5b43879b8af",
argocd-application-controller-0 application-controller - 		ResourceVersion:   "2187186233",
argocd-application-controller-0 application-controller + 		ResourceVersion:   "2187186273",
argocd-application-controller-0 application-controller   		Generation:        1,
argocd-application-controller-0 application-controller   		CreationTimestamp: {Time: s"2023-05-29 13:53:32 +0000 UTC"},
argocd-application-controller-0 application-controller   		... // 4 identical fields
argocd-application-controller-0 application-controller   		OwnerReferences: nil,
argocd-application-controller-0 application-controller   		Finalizers:      nil,
argocd-application-controller-0 application-controller   		ManagedFields: []v1.ManagedFieldsEntry{
argocd-application-controller-0 application-controller   			{
argocd-application-controller-0 application-controller   				Manager:     "kube-addon-manager",
argocd-application-controller-0 application-controller   				Operation:   "Apply",
argocd-application-controller-0 application-controller   				APIVersion:  "apiextensions.k8s.io/v1",
argocd-application-controller-0 application-controller - 				Time:        s"2023-11-27 22:37:40 +0000 UTC",
argocd-application-controller-0 application-controller + 				Time:        s"2023-11-27 22:37:41 +0000 UTC",
argocd-application-controller-0 application-controller   				FieldsType:  "FieldsV1",
argocd-application-controller-0 application-controller   				FieldsV1:    &{Raw: `{"f:metadata":{"f:annotations":{"f:components.gke.io/component-n`...},
argocd-application-controller-0 application-controller   				Subresource: "",
argocd-application-controller-0 application-controller   			},
argocd-application-controller-0 application-controller   			{Manager: "kube-apiserver", Operation: "Update", APIVersion: "apiextensions.k8s.io/v1", Time: s"2023-05-29 13:53:32 +0000 UTC", ...},
argocd-application-controller-0 application-controller   		},
argocd-application-controller-0 application-controller   	},
argocd-application-controller-0 application-controller   	Spec:

This PR just stop tracking those changes and fully skip the CRD reconciliation.

In case a real change is made to the CRD, the normal behavious applies:

argocd-application-controller-0 application-controller watchEvents mismatch for CRD after cleanup {apiextensions.k8s.io CustomResourceDefinition  lbpolicies.networking.gke.io} (-want +got):
argocd-application-controller-0 application-controller   v1.CustomResourceDefinition{
argocd-application-controller-0 application-controller   	TypeMeta: {Kind: "CustomResourceDefinition", APIVersion: "apiextensions.k8s.io/v1"},
argocd-application-controller-0 application-controller   	ObjectMeta: v1.ObjectMeta{
argocd-application-controller-0 application-controller   		... // 9 identical fields
argocd-application-controller-0 application-controller   		DeletionGracePeriodSeconds: nil,
argocd-application-controller-0 application-controller   		Labels:                     {"addonmanager.kubernetes.io/mode": "Reconcile"},
argocd-application-controller-0 application-controller   		Annotations: map[string]string{
argocd-application-controller-0 application-controller   			"components.gke.io/component-name":      "gateway-api-crds",
argocd-application-controller-0 application-controller   			"components.gke.io/component-version":   "0.7.0-gke.0",
argocd-application-controller-0 application-controller   			"components.gke.io/layer":               "addon",
argocd-application-controller-0 application-controller - 			"controller-gen.kubebuilder.io/version": "(unknown)",
argocd-application-controller-0 application-controller + 			"controller-gen.kubebuilder.io/version": "v1.0.0",
argocd-application-controller-0 application-controller   		},
argocd-application-controller-0 application-controller   		OwnerReferences: nil,
argocd-application-controller-0 application-controller   		Finalizers:      nil,
argocd-application-controller-0 application-controller   		ManagedFields:   {},
argocd-application-controller-0 application-controller   	},
argocd-application-controller-0 application-controller   	Spec:

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

No Coverage information
0.0% Duplication

[codecov]

Codecov Report

Attention: 30 lines in your changes are missing coverage. Please review.

Comparison is base (4a5648e) 54.70% compared to head (518494f) 54.36%.
Report is 1 commits behind head on master.

Files	Patch %	Lines
pkg/cache/cluster.go	0.00%	26 Missing ⚠️
pkg/sync/sync_context.go	82.60%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #555      +/-   ##
==========================================
- Coverage   54.70%   54.36%   -0.34%     
==========================================
  Files          41       41              
  Lines        4645     4672      +27     
==========================================
- Hits         2541     2540       -1     
- Misses       1908     1935      +27     
- Partials      196      197       +1     

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