added the API for events and modified the event database schema

[tanujvyas10]

Problem

Github Issue Number: #75

Type of Change

• [ ] Bug fix
• [x] New Feature
• [ ] Development of UI/UX prototypes
• [ ] Small refactor
• [ ] Change in Documentation

Checklist

• [x] My code follows the same style as the codebase
• [x] My Code change requires a change in documentation
• [ ] I have updated the Readme accordingly
• [x] I made PR against development branch
• [x] I have run the test cases locally and it's passing.
• [x] I have squashed my commits

[vaibhavdaren]

same as #114

[tanujvyas10]

same as #114

@vaibhavdaren @devesh-verma test cases have been added and are running successfully.

Please review now and let me know the latest

[vaibhavdaren]

@capedcrusader23 thankyou for a valuable review

[tanujvyas10]

@vaibhavdaren test cases passed successfully