Improve flows for social auth users (#13862)

* Multiple fixes for social authentication flows

* frontend changes

* add missing computed property

* Improvements to social flows

* fix existing email error

* minor fixes

* fix space

* fix test

* fix lint

Co-authored-by: SabreCat <sabe@habitica.com>

website/client/src/components/header/menu.vue

@@ -311,8 +311,8 @@
               </router-link>
               <a
                 class="topbar-dropdown-item dropdown-item"
-                @click.prevent="openBugReportModal()"
                 target="_blank"
+                @click.prevent="openBugReportModal()"
               >
                 {{ $t('reportBug') }}
               </a>