Enhance Customer and vendor due amount

[fmoric]

We need to enhance the Customer and Vendor Card page in Business Central by adding a new FlowField that shows the Due Amount of the customer.
Requirements:

1. Add a FlowField in the Customer/Vendor table extension that calculates the total due amount for the customer.
   ○ The field should reference the Detailed Cust. Ledg. Entry and Dtld. Vendor Ledger Entry
   ○ It must calculate the sum of Amount where Due Date is within the applied filter.
2. Enable a Date Filter on this FlowField so users can select a date range to dynamically view the due amounts.
3. Display the new field on the Customer/Vendor Card page so end users can easily access the information.
4. Filter Fields are not displayed on pages
   Acceptance Criteria:
   • A new field "Due Amount" is available on the Customer/Vendor Card.
   • The field correctly reflects the customer’s/Vendor's total outstanding due amounts.
   • Users can apply a date filter, and the field recalculates accordingly.
   • No performance degradation occurs when opening the Customer/Vendor Card.
   Notes:
   • Follow AL coding best practices. https://alguidelines.dev/ https://learn.microsoft.com/en-us/dynamics365/business-central/dev-itpro/
   • Ensure compatibility with existing customer extensions.