fix(Dataspreadsheet): add callback function for after drag/drop ends

[AustinGitHub]

Closes https://github.com/carbon-design-system/ibm-products/issues/5620

What did you change?

I added a callback method so user can know what new column headers are after drag/drop is done

How did you test and verify your work?

Storybook

https://github.com/carbon-design-system/ibm-products/assets/10100397/00c0e6d4-42de-4b5d-aaed-fb34c6bc7b99

[netlify[bot]]

✅ Deploy Preview for carbon-for-ibm-products ready!

Name	Link
🔨 Latest commit	d20576dca732157d32690c16cafa19a957753660
🔍 Latest deploy log	https://app.netlify.com/sites/carbon-for-ibm-products/deploys/668e998706669f000800b7cf
😎 Deploy Preview	https://deploy-preview-5621--carbon-for-ibm-products.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[AustinGitHub]

Added the fix, thanks!

[AustinGitHub]

https://github.com/carbon-design-system/ibm-products/assets/10100397/7624e79a-3189-4b0f-9b3c-dac3199671e2

Here is the fix