MSI with default product import

To use MSI with the default product import, the two following steps are necessary

Step 1: Add additional Column

Add the inventory_source_items column to be able to import MSI inventory data as well with the product import.

As for the tier prices, the column with the MSI inventory source items supports the same format.

source_code=default,quantity=10.0,status=1|source_code=inventory-01,quantity=5.0,status=1 (1)

1	The field `inventory_source_items` must contain the data in the given structure. Every line is seperated by a pipe ( `\|` )