Part of #20496: Replace deprecated mixins with Text component in selected-account.component.js

[devin-ai-integration]

Description

Replaced deprecated mixins with Text component in selected-account.component.js. The change aims to modernize the codebase by using the Text component from the design system, ensuring consistency and maintainability.

Devin Run Link: https://preview.devin.ai/devin/6dcddd7b3ee2456ca004b34d033b0d82

Related issues

Partially Fixes: MetaMask#20496

Manual testing steps

1. Go to the latest build of storybook in this PR
2. Verify the "SelectedAccount" component displays correctly with the updated Text component.

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I’ve followed MetaMask 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 (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.

[Devin-Apps]

Draft PR created - closing this