fix: ensure STX status updates across all networks

[httpJunkie]

Thanks for reviewing! Here's what you need to know about these changes:

Current State and Need for Change:

• Currently, when users have a pending Smart Transaction (STX) and switch to a different network, the STX status fails to update
• Users must switch back to the original network (Ethereum or BNB) to see status updates
• This blocks users from initiating new transactions on other networks until they switch back
• The root cause is that we're using the transaction's chainId instead of the storage key's chainId when fetching status updates

Solution:

• Modified updateSmartTransactions to consistently use the storage key's chainId instead of the transaction's chainId
• Added comprehensive tests to verify status updates work correctly across multiple networks
• The fix ensures that STX status updates happen regardless of which network the user is currently on
• Users can now freely switch networks without losing track of their pending transactions

Related Issues:

• Fixes [Bug]: STX status is not updated if user is on another network metamask-extension#31310
• This is the smart-transactions-controller portion of the fix for the extension issue

The changes are minimal but resolve a significant UX pain point where users were forced to switch back to original networks to see transaction status updates.

[httpJunkie]

The issue this fix was for seems to not be an issue anymore.