Introduce new module InventoryCatalog

[maghamed]

In a sake of better modularity of Inventory Domain.
It's proposed to introduce new module InventoryCatalog

With typical structure to Magento 2 modules

Read This Design for more details - https://github.com/magento-engcom/msi/wiki/The-Concept-of-Default-Source-and-Domain-Driven-Design

[naydav]

#102