[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

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

src/lib/async/timeout.ts

@@ -0,0 +1,3 @@
+export function timeout(ms: number): Promise<void> {
+  return new Promise(r => setTimeout(r, ms))
+}