chore: move data directories to ./data

[Gipphe]

Some manual steps are required once this PR is merged:

1. Move node-db to ./data/node

   mkdir -p ./data
   mv ./node-db ./data/node
   

2. Remove grafana-data, promtail-data, prometheus-data, loki-data, tempo-data and postgres-data. These all have to be recreated with the new paths.

   rm -i -rf grafana-data loki-data postgres-data prometheus-data promtail-data tempo-data
   

3. If you have a .env.local file with a custom DB_HOST, make sure to update this to the new path for data/postgres.

   echo "DB_HOST=<absolute path to repo dir>/data/postgres" > .env.local
   # Or edit it directly, if you have other stuff in there.