Replace custom build process with WP-Scripts

[iamdharmesh]

Description of the Change

PR replaces current custom build process with WP-Scripts also removes some legacy files which no longer needed

Closes #193

How to test the Change

1. Run npm install
2. Run npm run build
3. Make sure build files are generated successfully.
4. Smoke test plugin and make sure everything working fine

Changelog Entry

Changed - Replace custom build process with WP-Scripts

Credits

Props @iamdharmesh @peterwilsoncc

Checklist:

• 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.

[ravinderk]

@iamdharmesh The Pull request is looking good to me. I left a minor suggestion and a new issue which is not a blocker.

Let me know if you have any questions.

Additional issues:

• The Twitter icon is middle aligned in the column, which looks odd with other

[peterwilsoncc]

A couple of notes inline.

[jeffpaul]

@ravinderk @peterwilsoncc looking for updated review, thanks!

[ravinderk]

@iamdharmesh

I noticed the following:

• Eslint list issues in the pull request.
• E2E test GitHub workflow is failing.
• Few missing text domains from translatable strings.
  
  

Let me know if you have questions.

[iamdharmesh]

@ravinderk I have addressed PR feedback. Also, E2E tests are failing as we use build-release-zip.yml from develop and have made some changes in the build scripts. I temporarily pointed it to this PR branch to ensure E2E tests are running fine in this commit and it's E2E tests are passing. currently, I have rolled back it.