chore: refactor header for tokens

[brianacnguyen]

Description

This PR updates the Header for the Token details view, based on this design update by @amandaye0h . Specifically

• Left and right button icons are now using the ButtonIcon component with the large size
• Overflow icon is updated to vertical version
• Alignment of header is now top aligned

Related issues

Fixes: https://github.com/MetaMask/metamask-mobile/issues/11854

Manual testing steps

1. Go to Wallet
2. Click on a token

Screenshots/Recordings

Before

After

https://github.com/user-attachments/assets/e853d9a4-a9f2-4cc4-b186-19bb2ba69ee5

Pre-merge author checklist

• [x] I’ve followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• [x] I've completed the PR template to the best of my ability
• [ ] I’ve included tests if applicable
• [x] I’ve documented my code using JSDoc format if applicable
• [x] I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• [ ] I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• [ ] 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.