cue modules: move stdlib to pkg/alpha.dagger.io

In preparation for Europa, we will vendor multiple CUE modules:

- `pkg/alpha.dagger.io`: legacy non-europa packages
- `pkg/dagger.io`: core Europa packages
- `pkg/universe.dagger.io`: Europa universe

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

pkg/alpha.dagger.io/kubernetes/kustomize/tests/testdata/deployment.yaml

@@ -0,0 +1,22 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nginx-deployment
+  labels:
+    app: nginx-deployment
+spec:
+  replicas: 1
+  template:
+    metadata:
+      name: nginx-deployment
+      labels:
+        app: nginx-deployment
+    spec:
+      containers:
+        - name: nginx-deployment
+          image: nginx
+          imagePullPolicy: IfNotPresent
+      restartPolicy: Always
+  selector:
+    matchLabels:
+      app: nginx-deployment

pkg/alpha.dagger.io/kubernetes/kustomize/tests/testdata/pod.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: test-pod
+  labels:
+    app: test-pod
+spec:
+  containers:
+    - name: test-pod
+      image: nginx
+      imagePullPolicy: IfNotPresent
+  restartPolicy: Always