Improve some operations in account transactions.

- If a transaction is saved with source equals to destination account.
On Financial app, show a new transaction, with the same data of original,
but with inverted value.

- Set the source and destination accounts of transactions from payments,
according to operation type.
The selected account on payment confirmation, will be the source(for
payable payments) and destination(for receivable payments)

Change-Id: I88869bf2516fcdde086b0a5eba06f0b39919b013