- Adapted SourceItem Import/Export to use Source Code instead of SourceId;
- Fixed issue when in Stock Sources export process all fields ware excluded;
- Fixed type of return value for SourceItem->getSourceId method to int(was string);
- Adapted integrational test to the new Export/Import system(with source code).

…ask-290-import-export-source-code
Conflicts:
	app/code/Magento/InventoryApi/Test/_files/source.php
	app/code/Magento/InventoryApi/Test/_files/sources.php

- Fixed integration test.

- Fixed DependencyTest error.

- Changed SourceItem->getSourceId method.

- MEQP2 fixes;

- modified Source Item database structure(source_id changed to source_code);
- SourceId was replaced by SourceCode in MSI Extensions;

- source_id field usings ware replaced by source_code field - part;

- fixed foreign key issue with source_item_configuration setup schema;
- tests fixes - part;

- Fixed setup schema script for creatind default source;
- Tests fexes - part;

- fixed install schema/data issues;
- fixed issues on Source grid;
- identity field returned to source_id on Source mode;

…port-source-code
Conflicts:
	app/code/Magento/Inventory/Controller/Adminhtml/Stock/StockSourceLinkProcessor.php

- Fixed issue with with incorrect query on product edit page;

- Fixed issue with source item UIcomponent on product edit page

…port-source-code
Conflicts:
	app/code/Magento/InventoryApi/Test/_files/products.php

- Fixed issued with UI Components on stock edit page;

- Integration test fixes - part;

- Integration tests fixes - part;

- Test fixes -part;

- MEQP2 fixes;
- SourceImportExport integration tests fixes - part;
- Stock Source Import: modified sample file;

…om/magento-engcom/msi into task-290-import-export-source-code
Conflicts:
	app/code/Magento/InventoryImportExport/Files/Sample/stock_sources.csv