normalize responses and add types

src/library/artist/ArtistLibrary.vue

@@ -4,6 +4,7 @@
 <script lang="ts">
   import Vue from 'vue'
   import ArtistList from './ArtistList.vue'
+  import { Artist } from '@/shared/api'
 
   export default Vue.extend({
     components: {
@@ -11,7 +12,7 @@
     },
     data() {
       return {
-        items: []
+        items: [] as Artist[]
       }
     },
     created() {