[FEATURE] [issue-3283] Added Filter Support for Yes/No (boolean) attr…

[lewisvoncken]

…ibutes

Description

Currently it is only possible to set an attribute to is_filterable to attributes with catalog input type Dropdown, Multiple Select and Price. But in some cases you want a Yes/No (boolean) attribute to be filterable.

Fixed Issues (if relevant)

1. «Yes/No» attributes should be allowed in the Layered Navigation #3283: «Yes/No» attributes should be allowed in the Layered Navigation

Manual testing scenarios

Before:
1.

After:
1.

2.

3. After a reindex the attribute will be displayed as a filter!

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)

[magento-engcom-team]

Hi @lewisvoncken. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

• @magento-engcom-team give me test instance - deploy test instance based on PR changes
• @magento-engcom-team give me {$VERSION} instance - deploy vanilla Magento instance

For more details, please, review the Magento Contributor Assistant documentation

[lewisvoncken]

@magento-engcom-team

the PR Quality Review has not been analysed

[lewisvoncken]

@magento-engcom-team
Codacy coudn't run the analyses, let me know if this PR needs an update.

[magento-engcom-team]

Hi @slavvka, thank you for the review.
ENGCOM-3097 has been created to process this Pull Request

[magento-engcom-team]

Hi @lewisvoncken. Thank you for your contribution.
We will aim to release these changes as part of 2.2.8.
Please check the release notes for final confirmation.

Please, consider to port this solution to 2.3 release line.
You may use Porting tool to port commits automatically.