TS project references for translations plugin (#88022)

Observability has this as a dependency, so adding TS project references in service of that.

x-pack/plugins/translations/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "composite": true,
+    "outDir": "./target/types",
+    "emitDeclarationOnly": true,
+    "declaration": true,
+    "declarationMap": true
+  },
+  "include": ["server/**/*", "translations/ja-JP.json", "translations/zh-CN.json"],
+  "references": [{ "path": "../../../src/core/tsconfig.json" }]
+}

x-pack/tsconfig.json

@@ -14,6 +14,7 @@
     "plugins/security_solution/cypress/**/*",
     "plugins/task_manager/**/*",
     "plugins/telemetry_collection_xpack/**/*",
+    "plugins/translations/**/*",
     "plugins/ui_actions_enhanced/**/*",
     "test/**/*"
   ],
@@ -60,6 +61,7 @@
     { "path": "./plugins/licensing/tsconfig.json" },
     { "path": "./plugins/task_manager/tsconfig.json" },
     { "path": "./plugins/telemetry_collection_xpack/tsconfig.json" },
-    { "path": "./plugins/ui_actions_enhanced/tsconfig.json" },
+    { "path": "./plugins/translations/tsconfig.json" },
+    { "path": "./plugins/ui_actions_enhanced/tsconfig.json" }
   ]
 }

x-pack/tsconfig.refs.json

@@ -10,6 +10,7 @@
     { "path": "./plugins/embeddable_enhanced/tsconfig.json" },
     { "path": "./plugins/task_manager/tsconfig.json" },
     { "path": "./plugins/telemetry_collection_xpack/tsconfig.json" },
-    { "path": "./plugins/ui_actions_enhanced/tsconfig.json" },
+    { "path": "./plugins/translations/tsconfig.json" },
+    { "path": "./plugins/ui_actions_enhanced/tsconfig.json" }
   ]
 }