Extract initialisation SQL into separate file (#435)

This makes it easier to edit normally.

Also added a rule to `make format` which will use `npx sql-formatter` to format the file.

Makefile

@@ -9,6 +9,7 @@ clean:
 format:
 	# Format JSON schema
 	docker run --rm -v $$PWD/schema.json:/mnt/schema.json node:alpine npx prettier /mnt/schema.json --parser json --tab-width 2 --single-quote --trailing-comma all --no-semi --arrow-parens always --print-width 120 --write
+	docker run --rm -v $$PWD/pkg/state/init.sql:/mnt/init.sql node:alpine npx sql-formatter -l postgresql -o /mnt/init.sql /mnt/init.sql
 
 generate: format
 	# Generate the types from the JSON schema