feat: integrate pdf-signature-validator for native validation

Signed-off-by: Vitor Mattos <[email protected]>

Author: vitormattos

composer.json

@@ -1,4 +1,13 @@
 {
+	"repositories": [
+		{
+			"type": "path",
+			"url": "../pdf-signature-validator",
+			"options": {
+				"symlink": true
+			}
+		}
+	],
 	"require-dev": {
 		"bamarni/composer-bin-plugin": "^1.8",
 		"nextcloud/ocp": "dev-master",
@@ -63,6 +72,7 @@
 	"require": {
 		"cweagans/composer-patches": "^2.0",
 		"jeidison/signer-php": "^1.0",
+		"libresign/pdf-signature-validator": "*@dev",
 		"phpseclib/phpseclib": "^3.0"
 	}
 }