feat: add guard for import ledger page

[victorkirov]

🔘 PR Type

What kind of change does this PR introduce?

• Enhancement

📜 Background

We want to prevent the import ledger screen from being open more than once. We do this by closing any open import ledger tabs when a new one opens, similar to onboarding.

Issue Link: #ENG-2340

🔄 Changes

• Single tab guard was moved to its own component and used in the import ledger route, the onboarding guard, and the reset wallet guard
• When a wallet is reset, we now close all tabs

To be tested:

• Onboarding flow should be retested to ensure single tabs still work as expected
• Import ledger flow needs to be tested for single tabs
• We now close all open tabs when locking or resetting the wallet

✅ Review checklist

Please ensure the following are true before merging:

• Code Style is consistent with the project guidelines.
• Code is readable and well-commented.
• No unnecessary or debugging code has been added.
• Security considerations have been taken into account.
• The change has been manually tested and works as expected.
• Breaking changes and their impacts have been considered and documented.
• Code does not introduce new technical debt or issues.

[dhriaznov]

LGTM

[yknl]

Tested and working well.