Add WorldBank test

[nhintruong]

Adding WorldBank for the hard test in GSOC 2024 application

[tdhock]

great thanks for the contribution!
Can you please clarify if your new code tests any functionality which is not already covered in the other tests?

[nhintruong]

This is a testthat unit test based on one of my Animint visualizations, as requested in the hard test section here. I don't think there is any new functionality being tested. Please let me know if you would like me to do so.

[tdhock]

it would be good if you could check code coverage, and see if you could add a test that increases coverage.
this could be added to GSOC goals (computing coverage for R code on Github actions should be easy, would be nice if we could compute javascript coverage too)

[nhintruong]

Yes, I can do that. Should I add this to the test section in the proposal, or in one of the goals of the project?

[tdhock]

sure, you can add it to tests and goals
continue discussion about code coverage #122