ESLint: Auto format and fix some warnings / errors.

frontend/src/components/ActivityIndicator.vue

@@ -0,0 +1,28 @@
+<script setup lang="ts"></script>
+
+<template>
+    <div class="spinner-container">
+        <div class="spinner">
+            <i class="fa fa-refresh fa-spin fa-3x" aria-hidden="true" />
+            <span class="sr-only">Lädt...</span>
+        </div>
+    </div>
+</template>
+
+<style lang="scss" scoped>
+@import "../scss/variables";
+
+.spinner-container {
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+
+    display: flex;
+    align-items: center;
+    justify-content: center;
+
+    color: $page-text-color;
+}
+</style>