Issue 11175: fix i18n:collect-phrases so it also collects "translate args"

[PascalBrouwers]

Description

See issue #11175
fix i18n:collect-phrases so it also collects <translate args="'Items in Cart'"/>

Fixed Issues (if relevant)

1. i18n:collect-phrases -m can't find many important magento phrases  #11175: i18n:collect-phrases -m can't find many important magento phrases

Manual testing scenarios

1. run php bin/magento i18n:collect-phrases app/code/Magento/Checkout | grep "Items in Cart"
   Or when magento is in the vendor folder: php bin/magento i18n:collect-phrases vendor/magento/module-checkout | grep "Item in Cart"
2. It should return a line with: "Items in Cart","Items in Cart"

Contribution 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 on Travis CI are green)

[sidolov]

@PascalBrouwers , closed due to inactivity in the original pull request: #13470
Please, reopen if you wish to continue.
Thank you for collaboration!