🚚 ➕ add node-signpdf copy to signing packgage until npm includes fix

packages/signing/node-signpdf/dist/helpers/pdfkit/abstract_reference.js

@@ -0,0 +1,26 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+
+/*
+PDFAbstractReference by Devon Govett used below.
+The class is part of pdfkit. See https://github.com/foliojs/pdfkit
+LICENSE: MIT. Included in this folder.
+Modifications may have been applied for the purposes of node-signpdf.
+*/
+
+/*
+PDFAbstractReference - abstract class for PDF reference
+*/
+class PDFAbstractReference {
+  toString() {
+    throw new Error('Must be implemented by subclasses');
+  }
+
+}
+
+var _default = PDFAbstractReference;
+exports.default = _default;