(Draft) Add automated Nextcloud Talk recording backend deployment and configuration

Includes:
- Talk recording Docker service
- Schema credential for recording secret
- Compose integration
- Automatic Talk 'recording_servers' app config

Details: https://chatgpt.com/share/6920d8fc-81b4-800f-8d83-af22eeed94b5

roles/web-app-nextcloud/vars/plugins/spreed.yml

@@ -39,3 +39,19 @@ plugin_configuration:
   - appid: "spreed"
     configkey: "internal_secret"
     configvalue: "{{ NEXTCLOUD_HPB_INTERNAL_SECRET }}"
+
+  - appid: "spreed"
+    configkey: "recording_servers"
+    configvalue: >-
+      {{
+        {
+          'servers': [
+            {
+              'server': 'http://' ~ NEXTCLOUD_RECORDING_SERVICE ~ ':' ~ NEXTCLOUD_RECORDING_PORT ~ '/',
+              'verify': false
+            }
+          ],
+          'secret': NEXTCLOUD_RECORDING_SECRET
+        }
+        | to_json
+      }}