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/.dagger/env/os-container/.gitignore

@@ -0,0 +1,2 @@
+# dagger state
+state/**

pkg/alpha.dagger.io/.dagger/env/os-container/values.yaml

@@ -0,0 +1,28 @@
+plan:
+    package: ./os/tests/container
+name: os-container
+inputs:
+    SimpleSecret.cleartext:
+        text: hello, world!
+    SimpleSecret.encrypted:
+        secret: ENC[AES256_GCM,data:Ps0VwEr1g2VJAkuyvA==,iv:LWWhr6wjWhpiv46VIehkVK0p8gwd8S1atmiFYqWcdLI=,tag:lridOOyvkUlSa6n+e6rMPw==,type:str]
+sops:
+    kms: []
+    gcp_kms: []
+    azure_kv: []
+    hc_vault: []
+    age:
+        - recipient: age1gxwmtwahzwdmrskhf90ppwlnze30lgpm056kuesrxzeuyclrwvpsupwtpk
+          enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSB5SU9NUTRWWTBvZzRWZkNT
+            Tk5TWFBFcHBWMldNSXA4KzU3TlVwTU9pdEZJCkFXNWpMMmZOZGs3WTYxZ3hDZVpv
+            L3lYNVh3Ti9UQXZzaTNWRU9IdGh4UncKLS0tIDFxbE1ZTmlUNElWWmRIN2hSRjk4
+            azJIU2lIVlF4N1VxT2tVWDBPU2RsOEkKqkfxeT/mnnDxdvv/vhXMj2Zl8ogaAHa6
+            xbBUOaCZ8stwj4Zz4/iKdrPspQQKo7/QuxxAcFUfyuK3fULqJHPXPQ==
+            -----END AGE ENCRYPTED FILE-----
+    lastmodified: "2021-07-08T09:56:37Z"
+    mac: ENC[AES256_GCM,data:zDGloHwc2X2XQ5by1ZTPJyUihX4Zy9xgPUksHFKOhbXC/NvkUIrw/UWWEkcdyNWCuErQG+r/uGrY/h03rl2qFnpkxlabji4+wvUgNQ0ehO/z+LfL4fjweNBrNvCzwPlyTNOZAu4wFqc3iIwkwWDng4vnjZW6QwxZDL58otuOdfE=,iv:afSdXL5l/0HvF7FKJXKs5UtTMgpF+AbDW86VwWnRuGc=,tag:1F5MP75Uwq4OUiJ17hD+cA==,type:str]
+    pgp: []
+    encrypted_suffix: secret
+    version: 3.7.1