refactor: testnet icon in select Ledger address

[patricio0312rev]

[ledger] select address header should contain Testnet icon

Summary

• Testnet icon is now displayed in select address header.

## Screenshots

• Mainnet:

• Testnet:

Checklist

• I checked that both pnpm dev and pnpm dev:bare work as intended
• I checked the basic extension interactions and made sure wallet selection works
• I checked my UI changes against the design and there are no notable differences, including responsiveness
• I checked my (code) changes for obvious issues, debug statements and commented code
• I opened a corresponding card on Clickup for any remaining TODOs in my code
• I added a short description on how to test this PR (if necessary)
• Ready to be merged