[Backport] Refactor JavsScript for UrlRewrite module edit page.

[chirag-wagento]

Original Pull Request

#15422
Refactor JavaScript for admin module URL rewrite edit page

Description

Refactor JavaScript for admin module URL rewrite edit page

Fixed Issues (if relevant)

#15356: Refactore javascript for module URL rewrite

Manual testing scenarios

1. Go to Marketing > URL Rewrites > Edit
2. Remove Request Path text box value and try to save it.

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 @ihor-sviziev, thank you for the review.
ENGCOM-2457 has been created to process this Pull Request

[magento-engcom-team]

Hi @chirag-wagento. Thank you for your contribution.
We will aim to release these changes as part of 2.1.15.
Please check the release notes for final confirmation.