Separate tool to backfill Payee field in older transactions

The “Transactions Optimizations” page can have a separate sub-feature to allow backfilling Payees for existing old transactions. Same as it works right now for transfers by finding them.

For example user already has “Amazon” payee. New transactions land into this Payee. But there’s no way to link old ones. New tool can search old transactions and suggest them to link to the selected Payee. User can review per-transaction, deselect the ones he thinks are not fit.