Upgrade to vue3 (#16)

* upgrade to vue 3.x and framework7 8.x
* change calendar plugin to vue-datepicker
* disable export button when user does not hava any transaction
* implement new pin code input
* append thousands separator in amount in exchange rates page

src/desktop-main.js

@@ -1,8 +1,6 @@
-import Vue from 'vue';
+import { createApp } from 'vue'
 
 import App from './Desktop.vue';
 
-new Vue({
-    el: '#app',
-    render: h => h(App),
-})
+const app = createApp(App);
+app.mount('#app');