feat(admin-*,dashboard): add dashboard i18n extensions (#13763)

* virtual i18n module

* changeset

* fallback ns

fallback to the default "translation" ns if the key isnt found. Allows to use a single "useTranslation("customNs")" hook for both custom and medusa-provided keys

* simplify merges

* optional for backward compat

* fix HMR

* fix generated deepMerge

* test

packages/admin/admin-shared/src/utils/deep-merge.ts

@@ -0,0 +1,26 @@
+import { isObject } from "./is-object"
+
+export function deepMerge(target: any, source: any) {
+    const recursive = (a:any, b:any) => {
+        if (!isObject(a)) {
+            return b
+        }
+        if (!isObject(b)) {
+            return a
+        }
+
+        Object.keys(b).forEach((key) => {
+            if (isObject((b as any)[key])) {
+                (a as any)[key] ??= {};
+                (a as any)[key] = deepMerge((a as any)[key], (b as any)[key])
+            } else {
+                (a as any)[key] = (b as any)[key]
+            }
+        })
+
+        return a
+    }
+
+    const copy = { ...target }
+    return recursive(copy, source)
+}

packages/admin/admin-shared/src/utils/index.ts

@@ -0,0 +1 @@
+export * from "./deep-merge"

packages/admin/admin-shared/src/utils/is-object.ts

@@ -0,0 +1,3 @@
+export function isObject(obj: any): obj is object {
+  return obj != null && obj?.constructor?.name === "Object"
+}