feat: add displayLang test (#5495)

* feat(e2e): add language extension to setup

This adds a slimmed-down version of the Spanish Language Pack and also
adds a `languagepacks.json` to the e2e `workspaceDir` which allows use
to run a test suite passing the `--locale es` flags to simulate a
different display language.

* feat: add e2e test for display language patch

This tests loading code-server in Spanish using the `--locale` flag.

* fixup!: use JSON.stringify for readability

* fixup!: add comment about langaugepacks temp fix

* fixup!: slim down translations

* fixup!: slim down package.json for lang. ext

test/e2e/extensions/ms-ceintl.vscode-language-pack-es-1.70.0/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "vscode-language-pack-es",
+  "displayName": "Spanish Language Pack for Visual Studio Code",
+  "description": "Language pack extension for Spanish",
+  "version": "1.70.0",
+  "publisher": "MS-CEINTL",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/Microsoft/vscode-loc"
+  },
+  "engines": {
+    "vscode": "^1.70.0"
+  },
+  "categories": [
+    "Language Packs"
+  ],
+  "contributes": {
+    "localizations": [
+      {
+        "languageId": "es",
+        "languageName": "Spanish",
+        "localizedLanguageName": "español",
+        "translations": [
+          {
+            "id": "vscode",
+            "path": "./translations/main.i18n.json"
+          }
+        ]
+      }
+    ]
+  }
+}

test/e2e/extensions/ms-ceintl.vscode-language-pack-es-1.70.0/translations/main.i18n.json

@@ -0,0 +1,15 @@
+{
+  "": [
+    "--------------------------------------------------------------------------------------------",
+    "Copyright (c) Microsoft Corporation. All rights reserved.",
+    "Licensed under the MIT License. See License.txt in the project root for license information.",
+    "--------------------------------------------------------------------------------------------",
+    "Do not edit this file. It is machine generated."
+  ],
+  "version": "1.0.0",
+  "contents": {
+    "vs/workbench/contrib/files/browser/explorerViewlet": {
+      "explore": "Explorador"
+    }
+  }
+}