feat(wallet): wire TransactionController into default initialization

[matthewwalsh0]

Summary

• Wires TransactionController into the wallet package's default initialization
• Uses TransactionControllerMessenger directly (no separate init messenger) — same pattern as ApprovalController and KeyringController
• Delegates all AllowedActions and AllowedEvents from the root messenger to the controller messenger via parent.delegate
• Hardcodes incomingTransactions: { isEnabled: () => false } as both extension and mobile share this value
• Exposes TransactionControllerInstanceOptions (omits messenger, state, incomingTransactions) in instanceOptions.transactionController

[matthewwalsh0]

Closing — work moved back to #8975