Business Layer; optimise finAccount.CanRestructure function

The finAccount.CanRestructure function touches the finAccount.Calculation object, which loads that information and performs a future calculation. This was used to test if the Loan uses precomputed Contractual Interest.

This can slow down the user interface if this information is not already loaded.

This function has been optimised to not use the Calculation object if it is not loaded. Instead this setting is checked from the Account Type.