add page to show mnemonic seed phrase for backup

src/views/ContactsView.vue

@@ -232,6 +232,7 @@
     </ul>
   </section>
 
+  <!-- This same popup code is in many files. -->
   <div v-bind:class="computedAlertClassNames()">
     <button
       class="close-button bg-slate-200 w-8 leading-loose rounded-full absolute top-2 right-2"
@@ -251,7 +252,6 @@ import * as R from "ramda";
 import { IIdentifier } from "@veramo/core";
 import { Options, Vue } from "vue-class-component";
 
-import { AppString } from "@/constants/app";
 import { accountsDB, db } from "@/db";
 import { Contact } from "@/db/tables/contacts";
 import { MASTER_SETTINGS_KEY } from "@/db/tables/settings";
@@ -828,16 +828,15 @@ export default class ContactsView extends Vue {
     }
   }
 
+  // This same popup code is in many files.
   alertTitle = "";
   alertMessage = "";
   isAlertVisible = false;
-
   public onClickClose() {
     this.isAlertVisible = false;
     this.alertTitle = "";
     this.alertMessage = "";
   }
-
   public computedAlertClassNames() {
     return {
       hidden: !this.isAlertVisible,