fix: use lodash merge to merge request init objects

We have properties like header, that contain objects that need to be
merged recursively.

src/api.ts

 import { defineStore } from 'pinia'
 import { computed, readonly, ref, Ref } from 'vue'
+import { merge } from 'lodash'
 
 type ID = number | string
 
@@ -100,11 +101,14 @@ export function createExtendableAPI<T extends APIObject>(
     customRequestData: RequestInit | undefined,
     defaultRequestData?: RequestInit | undefined,
   ) {
-    return new Request(url, {
-      ...(defaultRequestData ?? {}),
-      ...(options?.getRequestDefaults?.() ?? {}),
-      ...(customRequestData ?? {}),
-    })
+    return new Request(
+      url,
+      merge(
+        options?.getRequestDefaults?.() ?? {},
+        defaultRequestData ?? {},
+        customRequestData ?? {},
+      ),
+    )
   }
 
   function reset() {