add lastfm and musicbrainz links to artist page

src/shared/components/ExternalLink.vue

@@ -0,0 +1,8 @@
+<template functional>
+  <a :href="props.href"
+    target="_blank"
+    rel="noopener noreferrer"
+    :class="[data.class, data.staticClass]">
+    <slot/>
+  </a>
+</template>

src/shared/components/index.ts

@@ -1,4 +1,5 @@
 import Vue from 'vue';
+import ExternalLink from "./ExternalLink.vue";
 import Icon from "./Icon.vue";
 import OverflowMenu from "./OverflowMenu.vue";
 import Spinner from "./Spinner.vue";
@@ -6,6 +7,7 @@ import Tiles from "./Tiles.vue";
 import Tile from "./Tile.vue";
 
 const components = {
+  ExternalLink,
   Icon,
   OverflowMenu,
   Spinner,