[APP-775] Add Welcome screen after account creation (#1038)

* add comments to step 1-3

* add onboarding screen

* add analytics for onboarding tracking

* fix useEffect

* change text

* change icon size

* put onboarding into bottom sheet modal instead of react navigation

* wip

* Simplify the type validation

* Fix: only trigger onboarding modal when account creation succeeds

* Add the 'session-ready' event which fires when the new session is stable

* Use the 'session-ready' event to trigger the onboarding modal

* update copy

* update copy

---------

Co-authored-by: Paul Frazee <pfrazee@gmail.com>

src/state/models/ui/shell.ts

@@ -127,6 +127,10 @@ export interface PreferencesHomeFeed {
   name: 'preferences-home-feed'
 }
 
+export interface OnboardingModal {
+  name: 'onboarding'
+}
+
 export type Modal =
   // Account
   | AddAppPasswordModal
@@ -158,6 +162,9 @@ export type Modal =
   | WaitlistModal
   | InviteCodesModal
 
+  // Onboarding
+  | OnboardingModal
+
   // Generic
   | ConfirmModal