Add PDF signature zone parsing functionality

This update introduces new services into the ChillDocStoreBundle for signature zone parsing within PDFs. The PDFSignatureZoneParser service identifies signature zones within PDF content while the additional classes, PDFPage and PDFSignatureZone, help define these zones and pages. Corresponding tests have also been

src/Bundle/ChillDocStoreBundle/Service/Signature/PDFSignatureZone.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\DocStoreBundle\Service\Signature;
+
+final readonly class PDFSignatureZone
+{
+    public function __construct(
+        public float $x,
+        public float $y,
+        public float $height,
+        public float $width,
+        public PDFPage $PDFPage,
+    ) {}
+
+    public function equals(self $other): bool
+    {
+        return
+            $this->x == $other->x
+            && $this->y == $other->y
+            && $this->height == $other->height
+            && $this->width == $other->width
+            && $this->PDFPage->equals($other->PDFPage);
+    }
+}