Add Catalog Feature to Custom Order Lines Extension

[Paulius11]

Is your feature request related to a problem? The current custom Order lines extension lacks a catalog feature, which is available in the Purchase module. This limits the ability to easily select and add products from a predefined catalog when creating or editing orders.

Describe the solution you'd like Implement a "Catalog" button or feature in the custom Order lines extension, similar to the one in the Purchase module. This would allow users to:

Access a product catalog directly from the order line interface
Select products from the catalog to add to the order
Automatically populate product details (e.g., description, unit price) when selecting from the catalog

Describe alternatives you've considered

Manually entering product details for each order line
Creating a separate product lookup function and copying details into order lines
Modifying the existing Purchase module to work with custom orders