use messages in template & add automatic page titling from route name

src/pages/Library.vue

@@ -32,16 +32,6 @@ export default {
     TextCard
   },
 
-  metaInfo () {
-    return {
-      title: this.groups.length ? 'Bibliothèque - ' + this.groups[0].id : 'Bibliothèque',
-      meta: [
-        { charset: 'utf-8' },
-        { name: 'viewport', content: 'width=device-width, initial-scale=1' }
-      ]
-    }
-  },
-
   props: {
     mode: { type: String, required: true },
     texts: { type: Array, required: true }