Extract library from plugin

sync-client/src/utils/hash.ts

@@ -0,0 +1,12 @@
+// https://stackoverflow.com/questions/7616461/generate-a-hash-from-string-in-javascript
+export function hash(content: Uint8Array): string {
+	let result = 0;
+	// eslint-disable-next-line @typescript-eslint/prefer-for-of
+	for (let i = 0; i < content.length; i++) {
+		result = (result << 5) - result + content[i];
+		result |= 0; // Convert to 32bit integer
+	}
+	return Math.abs(result).toString(16);
+}
+
+export const EMPTY_HASH = hash(new Uint8Array(0));