Deparser: Add optional formatting/pretty printing

[lfittl]

See https://github.com/pganalyze/libpg_query/pull/293

We should hold off on merging until we have a tagged libpg_query release. For context, this was updated locally to the latest libpg_query 17-latest tip, through pointing the update_source task to a local checkout, but we need to actually tag a release on libpg_query to make that task work as expected.