feat(cloudfront): Support creating Key Value Stores

This adds an initial resource to support creating a Key Value Store and
specifying an import source. Unfortunately, CloudFormation doesn't seem
to support specifying the `KeyValueStoreAssociations` property of a
function so there isn't a way to actually associate the store with a
function.

packages/@aws-cdk-testing/framework-integ/test/aws-cloudfront/test/integ.key-value-store.js.snapshot/integ-key-value-store.template.json

@@ -0,0 +1,64 @@
+{
+ "Resources": {
+  "TestKeyValueStore8D0C09A2": {
+   "Type": "AWS::CloudFront::KeyValueStore",
+   "Properties": {
+    "Comment": "A test Key Value Store for CloudFront",
+    "ImportSource": {
+     "SourceArn": {
+      "Fn::Join": [
+       "",
+       [
+        "arn:",
+        {
+         "Ref": "AWS::Partition"
+        },
+        ":s3:::",
+        {
+         "Fn::Sub": "cdk-hnb659fds-assets-${AWS::AccountId}-${AWS::Region}"
+        },
+        "/9c0f502203ec9d802046021b8a20affe8fd26234f67dcf2e93db5142bc2991a1.json"
+       ]
+      ]
+     },
+     "SourceType": "S3"
+    },
+    "Name": "integkeyvaluestoreTestKeyValueStore737B4C4B"
+   }
+  }
+ },
+ "Parameters": {
+  "BootstrapVersion": {
+   "Type": "AWS::SSM::Parameter::Value<String>",
+   "Default": "/cdk-bootstrap/hnb659fds/version",
+   "Description": "Version of the CDK Bootstrap resources in this environment, automatically retrieved from SSM Parameter Store. [cdk:skip]"
+  }
+ },
+ "Rules": {
+  "CheckBootstrapVersion": {
+   "Assertions": [
+    {
+     "Assert": {
+      "Fn::Not": [
+       {
+        "Fn::Contains": [
+         [
+          "1",
+          "2",
+          "3",
+          "4",
+          "5"
+         ],
+         {
+          "Ref": "BootstrapVersion"
+         }
+        ]
+       }
+      ]
+     },
+     "AssertDescription": "CDK bootstrap stack version 6 required. Please run 'cdk bootstrap' with a recent version of the CDK CLI."
+    }
+   ]
+  }
+ }
+}