Delete unused modals and invite code stuff (#8244)

* delete waitlist modal, which doesn't exist

* delete invite code modal

* rip out copied invites persisted state

* delete invite query

* delete unused modal implementations

src/state/modals/index.tsx

@@ -15,14 +15,6 @@ export interface DeleteAccountModal {
   name: 'delete-account'
 }
 
-export interface WaitlistModal {
-  name: 'waitlist'
-}
-
-export interface InviteCodesModal {
-  name: 'invite-codes'
-}
-
 export interface ContentLanguagesSettingsModal {
   name: 'content-languages-settings'
 }
@@ -40,10 +32,6 @@ export type Modal =
   // Lists
   | UserAddRemoveListsModal
 
-  // Bluesky access
-  | WaitlistModal
-  | InviteCodesModal
-
 const ModalContext = React.createContext<{
   isModalActive: boolean
   activeModals: Modal[]