🧪 Add Integration tests

[vatz88]

Add integration tests, possibly using playwright

[therealsujitk]

I'd also like to write a unit test to check if all the slots present in the generated *courses_.json** are present in the respective schema. It should be alright to use the same library for this right?

Edit: I've added XLSX tests in jest because Playwright seemes to be only for browser testing.

[vatz88]

Yes, jest is fine.

We can in future explore moving to vite and vitest from our current setup of parcel and jest

[therealsujitk]

Later we'll have to add one more test to check if the schemas are of the right format.