refactor: promote shared methods from concrete adapters to SQL.php

Promote 17 methods to SQL.php as concrete defaults, eliminating
duplicate implementations across MariaDB, Postgres, and SQLite.

Promoted: insertRequiresAlias, getPDOType, getRandomOrder, quote,
getInternalIndexesKeys, getMinDateTime, getMaxDateTime,
analyzeCollection, getSQLCondition, getSQLType, createSchemaBuilder,
createRelationship, updateRelationship, deleteRelationship,
deleteCollection, delete, getSpatialSQLType.

Net reduction: -325 lines across the adapter hierarchy.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: abnegate