Change ND genre ids to b64 encoded strings of genre, so as to differentiate between genre name and id (#54)

tests/b64.test.ts

@@ -0,0 +1,17 @@
+import { b64Encode, b64Decode } from "../src/b64";
+
+describe("b64", () => {
+    const value = "foobar100";
+    const encoded = Buffer.from(value).toString("base64");
+
+    describe("encode", () => {
+        it("should encode", () => {
+            expect(b64Encode(value)).toEqual(encoded);
+        });
+    });
+    describe("decode", () => {
+        it("should decode", () => {
+            expect(b64Decode(encoded)).toEqual(value);
+        });
+    });
+});