Check for duplicates which have been submitted by the author

[Celeron64]

Please check the following boxes

All boxes are required

• [x] I agree to the Contribution Guidelines and to the Code of Conduct
• [x] I tested my code and I verified it's working to the best of my ability
• [x] I checked if my code doesn't violate the styleguide with npm test

Describe your pull request

Adds a check to see if any of the suggestions which are being marked as duplicates were submitted by the person who is attempting to mark the suggestion as a duplicate.

Why is this change needed?

This can prevent 'XP Farming'

Does your pull request solve an open issue? If yes, please mention what one

This PR does not solve any open issues that I am aware of.

[Celeron64]

Hey there, thanks for raising your concerns. I've gone ahead and updated the code to fix the issue you mentioned.

Cheers, Celeron