🔧(backend) add view to manage footer json

We added the `FRONTEND_URL_JSON_FOOTER` environment
variable. It will give the possibility to generate
your own footer content in the frontend.
If the variable is not set, the footer will not
be displayed.

src/backend/core/services/config_services.py

@@ -0,0 +1,25 @@
+"""Config services."""
+
+import logging
+
+import requests
+
+logger = logging.getLogger(__name__)
+
+
+def get_footer_json(footer_json_url: str) -> dict:
+    """
+    Fetches the footer JSON from the given URL."
+    """
+    try:
+        response = requests.get(
+            footer_json_url, timeout=5, headers={"User-Agent": "Docs-Application"}
+        )
+        response.raise_for_status()
+
+        footer_json = response.json()
+
+        return footer_json
+    except (requests.RequestException, ValueError) as e:
+        logger.error("Failed to fetch footer JSON: %s", e)
+        return {}