Finish tests

- Add sub-doc handling for SQLite fields
- Add casting for PostgreSQL BT on numeric value
- Add hasItems() to DocumentList
- Fix SQL syntax problems exposed by tests

tests/integration/sqlite/DefinitionTest.php

@@ -4,11 +4,13 @@ namespace Test\Integration\SQLite;
 
 use BitBadger\PDODocument\{Custom, Definition, DocumentException};
 use BitBadger\PDODocument\Mapper\ExistsMapper;
+use PHPUnit\Framework\Attributes\TestDox;
 use PHPUnit\Framework\TestCase;
 
 /**
  * SQLite integration tests for the Definition class
  */
+#[TestDox('Definition (SQLite integration)')]
 class DefinitionTest extends TestCase
 {
     /** @var string Database name for throwaway database */