Enable SQLite column metadata

Build Unix SQLite with SQLITE_ENABLE_COLUMN_METADATA so the metadata APIs are available on macOS and Linux.

Remove the pdo_sqlite configure override that forced PHP to treat sqlite3_column_table_name() as unavailable, and add sanity checks for both SQLite compile options and PDO column metadata.

src/globals/ext-tests/sqlite3.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+$sqlite = new SQLite3(':memory:');
+$enabled = $sqlite->querySingle("SELECT sqlite_compileoption_used('ENABLE_COLUMN_METADATA')");
+
+if ((int) $enabled !== 1) {
+    throw new RuntimeException('SQLite was not built with SQLITE_ENABLE_COLUMN_METADATA.');
+}