feat: font size and extension dimensions update (WIP)

[georgewrmarshall]

Description

This PR updates the MetaMask extension's default typography and dimensions to improve readability and provide more space for content:

1. Typography Changes:

   • Updates the Text component to use large typography variables by default (16px font size). Note that this does not update all typography—any static SCSS using font-size will remain unchanged.
   • Removes the responsive typography behavior, standardizing on the larger size across all screen sizes
   • This change will make text more readable across the extension

2. Extension Dimension Updates:

   • Increases the extension width from 357px to 400px
   • Updates this dimension across multiple files including popup windows, modals, and UI components
   • Provides more horizontal space for content while maintaining the height at 600px also allows for larger font size

These changes are part of our efforts to improve the overall user experience and readability of the MetaMask extension.

Related issues

Fixes: https://github.com/MetaMask/MetaMask-planning/issues/3997

Manual testing steps

1. Build and run the extension locally or download the build
2. Verify the extension popup opens at 400px width
3. Check various text components to ensure they're using the larger typography
4. Verify modals and other UI components properly adjust to the new width
5. Test across different pages (unlock page, main wallet view, etc.) to ensure consistent sizing

Screenshots/Recordings

Before

• Extension width: 357px
• Smaller default typography with responsive scaling

before.extension720.mov

After

• Extension width: 400px
• Larger, consistent typography (16px base size)

extension.after.mov

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards
• 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 format if applicable
• I've applied the right labels on the PR

Pre-merge reviewer checklist

• I've manually tested the PR
• 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

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.