lots of progress on apple music integration

frontend/src/client/appleMusic/index.js

@@ -0,0 +1,47 @@
+const app = Vue.createApp( {
+    data() {
+        return {
+            musicKit: null,
+            isLoggedIn: false,
+        }
+    },
+    methods: {
+        logInto() {
+            if ( !this.musicKit.isAuthorized ) {
+                this.musicKit.authorize().then( () => {
+                    this.musicKit.play();
+                    this.isLoggedIn();
+                } );
+            }
+        },
+        initMusicKit () {
+            fetch( '/getAppleMusicDevToken' ).then( res => {
+                if ( res.status === 200 ) {
+                    res.text().then( token => {
+                        // MusicKit global is now defined
+                        MusicKit.configure( {
+                            developerToken: token,
+                            app: {
+                                name: 'MusicPlayer',
+                                build: '2'
+                            }
+                        } );
+                        this.musicKit = MusicKit.getInstance();
+                        if ( this.musicKit.isAuthorized ) {
+                            this.isLoggedIn = true;
+                        }
+                    } );
+                }
+            } );
+        }
+    },
+    created() {
+        if ( !window.MusicKit ) {
+            document.addEventListener( 'musickitloaded', () => {
+                self.initMusicKit();
+            } );
+        } else {
+            this.initMusicKit();
+        }
+    },
+} ).mount( '#app' );