netlify: Europa port

- Fix netlify.#Deploy (there's still FIXMEs)
- Externalize the `deploy.sh` script
- Add tests
- Misc engine fixes for more explicit error messages

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

pkg/universe.dagger.io/test_secrets.yaml

@@ -0,0 +1,21 @@
+netlifyToken: ENC[AES256_GCM,data:DeTBgf73iiIDVJZ3i1Rd6Cn9KvJGwh7n8/u/zWKdpaMvU7R1X43JqMbZMg==,iv:0HmdJr7BHKQk+RrCWAzZCkU7BkJ5N5//otgwAgJnQ6w=,tag:DoVYsCnO6HMHXpakX4uBlA==,type:str]
+sops:
+    kms: []
+    gcp_kms: []
+    azure_kv: []
+    hc_vault: []
+    age:
+        - recipient: age1gxwmtwahzwdmrskhf90ppwlnze30lgpm056kuesrxzeuyclrwvpsupwtpk
+          enc: |
+            -----BEGIN AGE ENCRYPTED FILE-----
+            YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBnUEhWbjV3M29oUUJyWk81
+            Wk1WQ1E0cmtuVlhNSGxkWUM3WmJXdUYvbzAwCjlFWW9IVmtmTjY1aU1LR2lxWFlT
+            am9RemNqSDRWK2FDYk1xeGNiTFlWMFUKLS0tIFVrSzBCMERQbnhYb09ReVpFK00v
+            TG5YUDlFVzlRRFBCdEhsNVlVK1dMRTgKx1TPZWWQiaU8iMni03/ekG+m4rFCcaa4
+            JI+ED2d+8411BgZtlss/ukQtwskidvYTvetyWw2jes6o1lhfDv5q2A==
+            -----END AGE ENCRYPTED FILE-----
+    lastmodified: "2022-01-20T00:42:44Z"
+    mac: ENC[AES256_GCM,data:N4dbowNmz34Hn/o1Ofv4g9Z5I7EzcYyrGpXSu9fkczd69zkTpv87uFamEdV/kQM2bbIEm9gS8d0oTi41qsC0iax368YUJmjG6xMptwrrA/mcjRzwXjlPrCZN9454srJw4NXWm0F5/aJQa4XlO65OCLZw+4WCz0wyAWwKzuQNAb0=,iv:EIG55jdEIbVp390uCVJ/rCjJO+s+CsAblH0/CIMNgIc=,tag:dcZDoMsBToikTQ83R0azag==,type:str]
+    pgp: []
+    unencrypted_suffix: _unencrypted
+    version: 3.7.1