feat!: implement entrypoints for PG extended protocol

BREAKING CHANGE!:
- pico.trace() function was removed. Use pico.sql() for tracing;
- opentelemetry tables __SBROAD_STAT and __SBROAD_QUERY were renamed
  into _SQL_STAT and _SQL_QUERY tables.

Introduce enrypoints for extended PG protocol:

- pg_bind: bind parameters to portal (IR) by descriptor;
- pg_close: remove portal from the storage by descriptor;
- pg_describe: get the portal metadata and type by descriptor;
- pg_execute: execute portal by descriptor;
- pg_parse: parse an SQL pattern into IR (reusing LRU),
  save IR into portal storage and return the descriptor;
- pg_portals: get a list of portal descriptors visible
  to the current user;

Co-authored-by: Kaitmazian Maksim <m.kaitmazian@picodata.io>