feat: added presigned url get routes for s3 document upload and download

[KevinBeltran23]

Developer: Kevin Beltran

Closes #48

Pull Request Summary

Created presigned url GET routes for file upload and download using S3

Modifications

I created a route.ts under api/download-url and api/upload-url
I also creates an aws-s3.ts file under lib

Testing Considerations

Double check it works

Pull Request Checklist

• Code is neat, readable, and works
• Comments are appropriate
• The commit messages follows our guidelines
• The developer name is specified
• The summary is completed
• Assign reviewers

Screenshots/Screencast

[aarav27]

Tested this through POSTMAN with a sample image and it works, well done! The only thing to add is the standard responses inside src/lib/response.ts.

[KevinBeltran23]

Did it. Let me know if anything still looks off. Thanks!

[aarav27]

Thanks for the changes, LGTM!