Expand Trigger parsing support

Hi folks,

Thanks @LucaCappelletti94 for stepping in. I was very excited to see "CREATE TRIGGER" support landing.

I just tried it it out and noticed that it's implemented for the Postgres and Generic dialects only, which is a great. I was wondering if there are any plans to extend support to other dialects? I'm most interest in sqlite: https://www.sqlite.org/lang_createtrigger.html with the biggest difference being inline functions bodies vs "execute function_name"

Thanks!

Start by reading the existing CREATE TRIGGER parsing support for the Postgres and Generic dialects, then compare it with SQLite's CREATE TRIGGER syntax at the linked SQLite documentation. Done means SQLite trigger statements, including inline function bodies, are accepted and covered by appropriate parser tests.

Written by the indexing model from the issue text.