Update Process handler semantics to include refunds

...king/application/service/TransactionProcessesService.java

.../pa165/banking/domain/process/handler/DepositHandler.java

...i/pa165/banking/domain/process/handler/RefundHandler.java

...a165/banking/domain/process/handler/ScheduledHandler.java

...pa165/banking/domain/process/handler/TransferHandler.java

...pa165/banking/domain/process/handler/WithdrawHandler.java

...a/cz/muni/pa165/banking/domain/remote/AccountService.java

...uni/pa165/banking/domain/transaction/TransactionType.java

...65/banking/domain/process/handler/DepositHandlerTest.java

.../banking/domain/process/handler/ScheduledHandlerTest.java

...5/banking/domain/process/handler/TransferHandlerTest.java