[Glitch] Add joined date to profiles in web UI

Port 2c77d97e0d to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/features/account/components/header.js

@@ -328,6 +328,8 @@ class Header extends ImmutablePureComponent {
                 )}
 
                 {account.get('note').length > 0 && account.get('note') !== '<p></p>' && <div className='account__header__content translate' dangerouslySetInnerHTML={content} />}
+
+                <div className='account__header__joined'><FormattedMessage id='account.joined' defaultMessage='Joined {date}' values={{ date: intl.formatDate(account.get('created_at'), { year: 'numeric', month: 'short', day: '2-digit' }) }} /></div>
               </div>
             </div>
           )}

app/javascript/flavours/glitch/styles/components/accounts.scss

@@ -555,6 +555,17 @@
       color: $primary-text-color;
     }
 
+    .account__header__joined {
+      font-size: 14px;
+      padding: 5px 15px;
+      color: $darker-text-color;
+
+      .columns-area--mobile & {
+        padding-left: 20px;
+        padding-right: 20px;
+      }
+    }
+
     .account__header__fields {
       margin: 0;
       border-top: 1px solid lighten($ui-base-color, 12%);