Upgrade to JSqlParser 4.8

See https://github.com/JSQLParser/JSqlParser/releases/tag/jsqlparser-4.7 and more importantly https://jsqlparser.github.io/JSqlParser/migration.html.

The AST API changed a lot (so much that I would have expected a 5.0 instead of a 4.7...) so it's going to require some work. Fortunately, we don't seem to have any external dependency reusing jsqlparser, so it will mostly be about rewriting our own code.