added fake customer_id

gso/services/crm.py

+from typing import Optional
+
+
+def all_customers() -> list[dict]:
+    return [
+        {
+            "id": "8f0df561-ce9d-4d9c-89a8-7953d3ffc961",
+            "name": "Geant",
+        },
+    ]
+
+
+def get_customer_by_name(name: str) -> Optional[dict]:
+    for customer in all_customers():
+        if customer["name"] == name:
+            return customer
+
+    return None