chore: optimise subquery-node build

Reorganises node.dockerfile into multistage with self-contained build process
Copied current docker-compose.yml into a new production-friendly prod-docker-compose.yml, not relying on volumes etc for faster iteration.

Code Review Checklist (to be filled out by reviewer)

[ ] Description accurately reflects what changes are being made.
[ ] Either the PR references an issue (via the "Development" combobox) or the description explains the need for the changes.
[ ] The PR appropriately sized.
[ ] The PR contains an idempotent DB migration.
[ ] I have verified the correctness of the DB migration using relevant data (e.g. test-generated data).
[ ] New code has enough tests.
[ ] New code has enough documentation to answer "how do I use it?" and "what does it do?".
[ ] Existing documentation is up-to-date, if impacted.