Add barcode-detector-api-polyfill dependency and update environment variable declarations in SvelteKit project

node_modules/@zxing/library/es2015/browser/BrowserDatamatrixCodeReader.d.ts

@@ -0,0 +1,13 @@
+import { BrowserCodeReader } from './BrowserCodeReader';
+/**
+ * @deprecated Moving to @zxing/browser
+ *
+ * QR Code reader to use from browser.
+ */
+export declare class BrowserDatamatrixCodeReader extends BrowserCodeReader {
+    /**
+     * Creates an instance of BrowserQRCodeReader.
+     * @param {number} [timeBetweenScansMillis=500] the time delay between subsequent decode tries
+     */
+    constructor(timeBetweenScansMillis?: number);
+}