feature #235 [Store][Pg] Add support for custom "where" expression (lyrixx)

This PR was merged into the main branch.

Discussion
----------

[Store][Pg] Add support for custom "where" expression

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| Docs?         | no
| Issues        |
| License       | MIT

I want to be able to filter some record before comparison.
Usage:

```php
$crawlAId = '013e951c-335f-4e2b-9414-9eedbf0f51df';
$crawlBId = '396af6fe-0dfd-47ed-b222-3dbcced3f38e';

$rows = $connection
    ->executeQuery(<<<SQL
        SELECT *
        FROM {$tableName}
        WHERE metadata->>'crawlId' = '{$crawlAId}'
    SQL)
    ->fetchAllAssociative()
;

foreach ($rows as $i => $row) {
    $vector = new Vector(json_decode($row['embedding'], true));
    $documents = $store->query(
        $vector,
        [
            'maxScore' => 0.1,
            'where' => "metadata->>'crawlId' = :crawlId AND id != :currentId",
            'params' => [
                'crawlId' => $crawlBId,
                'currentId' => $row['id'],
            ],
        ],
    );

    if (!$documents) {
        continue;
    }

    $metadata = json_decode($row['metadata'], true, 512, \JSON_THROW_ON_ERROR);
    echo "Current document: {$metadata['url']}\n";
    foreach ($documents as $i => $document) {
        echo "- {$document->metadata['url']} (score: {$document->score})\n";
        if ($i >= 1) {
            break;
        }
    }
    echo "\n";
}

```

Commits
-------

3bdcb79 [Store][Pg] Add support for custom "where" expression

Author: OskarStark

src/store/src/Bridge/Postgres/Store.php

@@ -92,7 +92,20 @@ public function add(VectorDocument ...$documents): void
      */
     public function query(Vector $vector, array $options = []): array
     {
+        $where = null;
+
         $maxScore = $options['maxScore'] ?? null;
+        if ($maxScore) {
+            $where = "WHERE ({$this->vectorFieldName} {$this->distance->getComparisonSign()} :embedding) <= :maxScore";
+        }
+
+        if ($options['where'] ?? false) {
+            if ($where) {
+                $where .= ' AND ('.$options['where'].')';
+            } else {
+                $where = 'WHERE '.$options['where'];
+            }
+        }
 
         $sql = \sprintf(<<<SQL
             SELECT id, %s AS embedding, metadata, (%s %s :embedding) AS score
@@ -105,13 +118,14 @@ public function query(Vector $vector, array $options = []): array
             $this->vectorFieldName,
             $this->distance->getComparisonSign(),
             $this->tableName,
-            null !== $maxScore ? "WHERE ({$this->vectorFieldName} {$this->distance->getComparisonSign()} :embedding) <= :maxScore" : '',
+            $where ?? '',
             $options['limit'] ?? 5,
         );
         $statement = $this->connection->prepare($sql);
 
         $params = [
             'embedding' => $this->toPgvector($vector),
+            ...$options['params'] ?? [],
         ];
         if (null !== $maxScore) {
             $params['maxScore'] = $maxScore;