Replace custom checks from the server script to use concurrently

[KshitijThareja]

Description

This PR replace the use of custom script to handle server startup and termination with concurrently.

Issue addressed

#676

Changelog

• [#PR no]
  • Description: Replaces custom configuration in runVisualTests.js for server startup and termination by concurrently. Also migrate other essential checks to visual.index.js thereby eliminating the need for a custom script.
  • Products impact: -
  • Addresses: Visual Testing: Replace the current run script to use concurrently #676
  • Components: -
  • Breaking: -
  • Impacts a11y: -
  • Guidance: -

[#PR no]: PR link

Steps to test

1. Add the PERCY_TOKEN env variable before running tests.
2. Run the tests using yarn test:visual to see the new changes in action.

Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical and brittle code paths are covered by unit tests
• The change is described in the changelog section above

Reviewer guidance

• Is the code clean and well-commented?
• Are there tests for this change?
• Are all UI components LTR and RTL compliant (if applicable)?
• Add other things to check for here

After review

• The changelog item has been pasted to the CHANGELOG.md

Comments

[bjester]

I suppose you can remove this now

[KshitijThareja]

Oh yeah. Will make the changes 👍

[KshitijThareja]

Hi @bjester :)
Can this PR be merged now if there are no further changes required?

[bjester]

LGTM