[2.2-develop] Add static test to detect blocks without name attribute

[ihor-sviziev]

Description

This change covers an issue when block doesn't contain name attribute in layout file.
As was discussed in #10354 (comment) - need to covert missing block names issue with static test.

Fixed Issues (if relevant)

1. N/A

Related issues

1. Add missing block name to allow block customisation #10352: Add missing block name to allow block customisation
2. Add missing block name to allow block customisation #10354: Add missing block name to allow block customisation
3. #10824 add name for order items grid default renderer block #10936: Cannot add new columns to item grid in admin sales_order_view layout #10824 add name for order items grid default renderer block
4. Add static test to detect blocks without name attribute #11092 Add static test to detect blocks without name attribute

Manual testing scenarios

1. N/A

Contribution checklist

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

[mzeis]

The functional test suite timed out. I'll close and re-open the PR to trigger a new build.

[ihor-sviziev]

@mzeis now build is green. Thank you!