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/docker/tests/run-host/simple.cue

@@ -0,0 +1,21 @@
+package docker
+
+import (
+	"alpha.dagger.io/random"
+)
+
+TestConfig: {
+	host: string @dagger(input)
+}
+
+TestHost: {
+	suffix: random.#String & {
+		seed: "docker-tcp-test"
+	}
+
+	run: #Run & {
+		name: "daggerci-test-tcp-\(suffix.out)"
+		ref:  "hello-world"
+		host: TestConfig.host
+	}
+}