feat(pg): add materialized view dependsOn ordering

[JackTYM]

Summary

• Add .dependsOn() to pgMaterializedView to capture view dependencies.
• Persist dependsOn in snapshots/serialization for PG views.
• Order CREATE/DROP view statements topologically and recreate dependent views when a base view changes.

Usage

const baseView = pgMaterializedView('base_view', { id: integer('id') }).as(sql`SELECT "id" FROM ${users}`);
const aggView = pgMaterializedView('agg_view', { id: integer('id') })
  .dependsOn(baseView)
  .as(sql`SELECT "id" FROM "base_view"`);

Tests

   ✓ create materialized views in dependency order 1ms
   ✓ drop materialized views in dependency order 1ms
   ✓ recreate dependent materialized views when base changes 2ms

Fixes #4520