MQE-1541: Add option to generate:tests for XSD validation on 'merged files'

[soumyau]

Description

https://jira.corp.magento.com/browse/MQE-1541

• Added a --fastdebug (-a) option to generate:tests to run XSD validation against 'merged files'.
• Introduce a new .env parameter 'MFTF_FAST_DEBUG' that can be used to enable/disable fast debugging
• Logging xsd validation errors as CRITICAL in mftf log

5/16: Changes to the implementation as per recent discussions:
1. enable debugging for generate:tests by default
2. --debug runs developer mode allowing enhanced debugging
3. introduced input option 'ignore' to skip debugging for backward compatibility. To be removed in next MAJOR release

Fixed Issues (if relevant)

Fixed issue with mergedTestSchema error : Skipping pointless attribute use prohibition 'skipReadiness'

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/verification tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)
• Changes to Framework doesn't have backward incompatible changes for tests or have related Pull Request with fixes to tests

[magento-cicd2]

All committers have signed the CLA.

[KevinBKozan]

Some changes required to logger, but also have a bigger question around the new flag

[coveralls]

Coverage increased (+1.6%) to 56.241% when pulling f1f2381 on MQE-1541 into 9359af2 on develop.

[coveralls]

Coverage increased (+1.3%) to 55.958% when pulling a3f25bd on MQE-1541 into 9359af2 on develop.

[soumyau]

Some changes required to logger, but also have a bigger question around the new flag

Changed the implementation as per recent discussions:

1. enabled debugging for generate:tests by default
2. --debug runs developer mode allowing enhanced debugging
3. introduced input option 'ignore' to skip debugging for backward compatibility

[KevinBKozan]

Needs some changes as to how we are setting the mode, but conceptually it's good.
Also there's some skipReadiness changes that I don't think should be included in this PR.

[KevinBKozan]

Spoke in person with @soumyau. Decision was as follows:

• Keep --debug as optional
• Map --debug to developer for backwards compatibility
• Allow setting of debug level via --debug developer/production/default

[soumyau]

Updated as per recent discussions

[KevinBKozan]

QA finished, one small requirement but otherwise we should be good to go.