Allow decimal stock qty in feed builder

[shamoon]

Description (*)

If a store uses stock quantities that aren't ints the feed upload fails with e.g.

main.CRITICAL: Exception: Deprecated Functionality: Implicit conversion from float 9918.5 to int loses precision in .../vendor/meta/module-catalog/Model/Product/Feed/Builder/MultiSourceInventory.php on line 158 in .../vendor/magento/framework/App/ErrorHandler.php:61

Story

Bug

Task

Fixed Issues (if relevant)

1. magento-commerce/facebook-for-magento2#<issue_number>: Issue title

Manual testing scenarios (*)

1. Have a stock qty of eg 100.5
2. Trigger manual upload

Questions or comments

Checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)