Add command for creating notation configuration secrets

Signed-off-by: Jason <jagoodse@microsoft.com>

cmd/flux/testdata/create_secret/notation/secret-ca-crt.yaml

@@ -0,0 +1,28 @@
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: notation-config
+  namespace: my-namespace
+stringData:
+  ca.crt: ca-data-crt
+  trustpolicy.json: |
+    {
+        "version": "1.0",
+        "trustPolicies": [
+            {
+                "name": "fluxcd.io",
+                "registryScopes": [
+                    "*"
+                ],
+                "signatureVerification": {
+                    "level" : "strict"
+                },
+                "trustStores": [ "ca:fluxcd.io" ],
+                "trustedIdentities": [
+                    "*"
+                ]
+            }
+        ]
+    }
+