[Onboarding] Add starterpacks step (#9007)

* add onboarding starterpacks step

* tweak starter pack cards

* fix web styling

* use new API

* add screen transitions to onboarding

* skip host account

* bump limit to 6

* tweak font weight

* rm commented out code

* fix yarn.lock

* limit starter packs experiment to english speakers

src/lib/statsig/gates.ts

@@ -8,6 +8,7 @@ export type Gate =
   | 'feed_reply_button_open_thread'
   | 'old_postonboarding'
   | 'onboarding_add_video_feed'
+  | 'onboarding_suggested_starterpacks'
   | 'post_follow_profile_suggested_accounts'
   | 'remove_show_latest_button'
   | 'test_gate_1'