Feature: Group candidates by payee

[bobobo1618]

I typically have a large number of transactions for any given payee, all of which will be categorized as the same account (e.g. all purchases at the grocery store are classified as Expenses:Groceries).

Currently, all those purchases are spread, so I have to pay extra attention when importing.

If instead I knew I'd get all the transactions from the same store one after the other, I could be a bit more aggressive with my hammering of the Enter key.