Feat: Implement exists function on land

[capedcrusader21]

Description

Steps to update the Land contract on mainnet.

• run command: yarn deploy mainnet --tags LandV3

Checklist:

• [ ] Pull Request references Jira issue
• [ ] Pull Request applies to a single purpose
• [ ] I've added comments to my code where needed
• [ ] I've updated any relevant docs
• [ ] I've added tests to show that my changes achieve the desired results
• [ ] I've reviewed my code
• [ ] I've followed established naming conventions and formatting
• [ ] I've generated a coverage report and included a screenshot
• [ ] All tests are passing locally