Add JSON schema generation for kubeconform CRD validation

- ci/generate-schemas.sh fetches CRDs from the cluster via kubectl, supplements
  with offline CRD manifests (ArgoCD, Gateway API) and Kubernetes swagger spec
- Schemas use Datree catalog convention: <group>/<Kind>_<version>.json
- validate-apps.sh and validate-clusters.sh check local schemas first
- Makefile schemas target runs before kubeconform

Makefile

@@ -6,8 +6,12 @@ build:
 	@mkdir -p manifests/$(filter-out $@,$(MAKECMDGOALS))
 	@kustomize build --enable-helm $(filter-out $@,$(MAKECMDGOALS)) --output manifests/$(filter-out $@,$(MAKECMDGOALS))
 
+# Generate JSON schemas from CRDs and Kubernetes swagger spec
+schemas:
+	@ci/generate-schemas.sh schemas
+
 # kubeconform
-kubeconform:
+kubeconform: schemas
 	@ci/validate-apps.sh && \
 	ci/validate-clusters.sh