Profile redesign: Add alt to avatar and header (#38532)

app/javascript/mastodon/models/account.ts

@@ -62,6 +62,7 @@ export const accountDefaultValues: AccountShape = {
   acct: '',
   avatar: '',
   avatar_static: '',
+  avatar_description: '',
   bot: false,
   created_at: '',
   discoverable: false,
@@ -78,6 +79,7 @@ export const accountDefaultValues: AccountShape = {
   group: false,
   header: '',
   header_static: '',
+  header_description: '',
   id: '',
   last_status_at: '',
   locked: false,