Standard Transactions; new "per annum" option for percentage basis rates

A new "Per Annum" option for percentage basis Standard Transactions has been added.

This allows you to specify an annualised Rate, e.g. 12%, rather than a per frequency rate, e.g. 1% (if monthly).

It also helps with rounding errors on large values. For example, a fee of 1.75% per annum (charged monthly) on a Credit Limit of $5,000,000 is $7,291.67 per month - but a monthly rate of 0.1458% equates to $7,290.00.