[Forwardport] Refactor JavsScript for customer logout

[vijay-wagento]

Original Pull Request

#15301
Refactor JavaScript for front-end customer logout

Description

Remove JavaScript from logout.phtml and create JS component for that.

Fixed Issues (if relevant)

1. N/A

Manual testing scenarios

1. Login in front-end
2. Logout from front-end

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