Settings screen improvements

[MARQAS]

Description of the Change

This PR will merge the subscription name and id into one option along with some alignment improvements

Closes #2739

How to test the Change

• Go to ElasticPress settings screen Dashboard
• Notice that the Subscription ID and Username are merged into one option
• Observe the proper alignment of options

Changelog Entry

Changed - Settings screen options

Credits

Props @MARQAS

Checklist:

• [x] I agree to follow this project's Code of Conduct.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my change.
• [ ] All new and existing tests pass.