[Forwardport] Add missing table aliases to fields mapping for Customer Group filter…

[hitesh-wagento]

Original Pull Request

#15826
… and sorting processor #15822

Description

This PR is a fix for #15822. Issue is caused by missing table alias prefixes in field mappings for customer group filter and sorting processors.

Fixed Issues

1. SQL Error: ambiguous column 'customer_group_id' in 'All customers' page in admin when extension attribute table is joined #15822: SQL Error: ambiguous column 'customer_group_id' in 'All customers' page in admin when extension attribute table is joined

Manual testing scenarios

Follow the steps described in the relevant issue.

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)

[hitesh-wagento]

@dmanners Could you please check what cause failed travis?

Thanks,

[magento-engcom-team]

Hi @hitesh-wagento. Thank you for your contribution.
Changes from your Pull Request will be available with the upcoming 2.3.0 release.