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

.eslintrc.js

@@ -0,0 +1,14 @@
+module.exports = {
+    'root': true,
+    'env': {
+        'node': true
+    },
+    'extends': [
+        'eslint:recommended',
+        'plugin:vue/vue3-essential'
+    ],
+    'rules': {
+        "vue/multi-word-component-names": "off",
+        "vue/no-use-v-if-with-v-for": "off"
+    }
+}