Move modal frame parts away from modal-content into modal, improve error handling

src/components/async_component_error/async_component_error.vue

@@ -0,0 +1,41 @@
+<template>
+  <div class="async-component-error">
+    <div>
+      <h4>
+        {{ $t('general.generic_error') }}
+      </h4>
+      <p>
+        {{ $t('general.error_retry') }}
+      </p>
+      <button
+        class="btn"
+        @click="retry"
+        >
+        {{ $t('general.retry') }}
+      </button>
+    </div>
+  </div>
+</template>
+
+<script>
+export default {
+  methods: {
+    retry () {
+      this.$emit('resetAsyncComponent')
+    }
+  }
+}
+</script>
+
+<style lang="scss">
+.async-component-error {
+  display: flex;
+  height: 100%;
+  align-items: center;
+  justify-content: center;
+  .btn {
+    margin: .5em;
+    padding: .5em 2em;
+  }
+}
+</style>