Account Payment/Withdrawal/Refund/Transfer wizards; produced a number of Errors in debug window

Code has been tided up to reduce these errors displaying in the debug window. Most were caused when the form was loading and details had not yet been entered for various fields.

Account Payment
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1.CalculateInternal was called before an Account or Transaction Type or Value was entered and this caused errors in the debug window.

2. The Payment Control was validating banking details before a payment method was entered and this caused errors in the debug window.


Account Withdrawal
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1. CalculateInternal was called before an Account or Transaction Type was entered and this caused errors in the debug window.

2. Inbuilt script 'SummaryPage_AccountWithdrawal_WithdrawalSummay' has been updated.
2.1 Was accessing the TransactionTypes global collection when TransactionTypePk was 0.
2.2 May still write an error to the debug window due to the date entered; from finAccountPayArrangementAdd.Calculate
'Next Payment date cannot be prior to the date of this Payment Arrangement.'

Account Refund
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1. SummaryPage_AccountWithdrawal_WithdrawalSummay Script
May still write an error to the debug window after selecting an Account, due to the date entered; from finAccountPayArrangementAdd.Calculate.

Account Transfer
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1. CalculateInternal was called before an Account or Transaction Type was entered and this caused errors in the debug window.