Make warehouseId optional when creating orderLines - choose default warehouse for that product when not set

[madsoliver]

Our integration has a config "What warehouse should orderslines use". In most cases our clients only have one warehouse, so this works fine. But sometimes they forget to assign aome of their products to their "default" warehouse, causing issues when we try to create order(lines). Invalid warehouse ID for product.

A feature request is therefore:

1. Assign automatically the "main warehouse" to all new products.
2. Make it possible to have "default" warehouse for each product.
3. Make it possible to NOT set warehouseId when creating orders via API, and let Tripletex choose the default warehouse for that product/orderline

[madsoliver]

Looks like nr. 2 is allready possible, BUT there is no way to get info about what warehouse that is default for a product via API.

I made a separate issue : https://github.com/Tripletex/tripletex-api2/issues/52

[madsoliver]

bump