refactor: name supporting services and volumes by role

Rename database services to db and cache services to cache, with their
volumes as db-data and cache-data, in litellm, owncloud and goclaw. Rename
the couchbase and open-webui volumes to <service>-data. Data on miti-sg was
copied into the new volumes beforehand; the old volumes are kept.

open-webui/compose.yml

@@ -9,7 +9,7 @@ services:
       # - OPENAI_API_KEY=${OPENAI_API_KEY:-}
       # - OLLAMA_BASE_URL=${OLLAMA_BASE_URL:-}
     volumes:
-      - open-webui:/app/backend/data
+      - open-webui-data:/app/backend/data
     healthcheck:
       test: ["CMD", "curl", "-f", "http://127.0.0.1:8080"]
       interval: 5s
@@ -17,4 +17,4 @@ services:
       retries: 10
 
 volumes:
-  open-webui:
+  open-webui-data: