refactor(accounts): migrate wallet AccountSelector to design system (#29598)

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## **Description**

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migrate the wallet **AccountSelector** screen
(`app/components/Views/AccountSelector`) to
`@metamask/design-system-react-native` (BottomSheet, Button, Text).

## **Changelog**

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CHANGELOG entry: null

## **Related issues**

Fixes: https://consensyssoftware.atlassian.net/browse/MUL-1685

## **Manual testing steps**

- Open the "Account List" and check that there aren't any UI regressions

## **Screenshots/Recordings**


https://github.com/user-attachments/assets/460303fc-20e0-4eb6-83be-d32c698ec6ef

## **Pre-merge author checklist**

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- [ ] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've completed the PR template to the best of my ability
- [ ] I've included tests if applicable
- [ ] I've documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I've applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

#### Performance checks (if applicable)

- [ ] I've tested on Android
  - Ideally on a mid-range device; emulator is acceptable
- [ ] I've tested with a power user scenario
- Use these [power-user
SRPs](https://consensyssoftware.atlassian.net/wiki/spaces/TL1/pages/edit-v2/401401446401?draftShareId=9d77e1e1-4bdc-4be1-9ebb-ccd916988d93)
to import wallets with many accounts and tokens
- [ ] I've instrumented key operations with Sentry traces for production
performance metrics
- See [`trace()`](/app/util/trace.ts) for usage and
[`addToken`](/app/components/Views/AddAsset/components/AddCustomToken/AddCustomToken.tsx#L274)
for an example

For performance guidelines and tooling, see the [Performance
Guide](https://consensyssoftware.atlassian.net/wiki/spaces/TL1/pages/400085549067/Performance+Guide+for+Engineers).

## **Pre-merge reviewer checklist**

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- [ ] I've manually tested the PR (e.g. pull and build branch, run the
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- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Medium risk because this refactors a user-facing modal/sheet UI,
removes the existing reanimated slide/backdrop behavior, and changes
safe-area/keyboard offset handling, which could introduce visual
regressions or layout issues.
> 
> **Overview**
> Migrates `AccountSelector` UI from custom `StyleSheet`/legacy
component-library `Button`+`Text` and reanimated backdrop/slide-in
animation to design-system `Box`/`Button`/`Text` with Tailwind classes,
deleting `AccountSelector.styles.ts`.
> 
> Simplifies close behavior to a direct `navigation.goBack()` and
adjusts `KeyboardAvoidingView` positioning using
`useSafeAreaFrame`/insets; also changes Sentry tracing to start in
`useLayoutEffect` and end after paint instead of tying trace completion
to the removed animation callback.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
4b27c58. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: gantunesr