Hey Mayank,
You are right, there is no more a field to upload eMedical tracking sheet. (It used to be there earlier, I checked before I actually took the upfront medical exam). I was confused myself but I ended up submitting the application without medical tracking sheet assuming IRCC just upgraded their system and that they could easily fetch my medical results using my nationality and passport number (both of which are unique to me, are there in the emedical system, and IRCC obviously has them).
I was wrong. Few days after submission, I received a medical instruction letter. (at least 3 others in this very thread faced the same issue). The hospital told me to talk to the embassy as they could not do the medical again because the old one was valid for an year. I have been writing webforms since then and it's now more than 30 days since the medical request and the issue still hasn't been fixed.
I suggest you to take the paper route and attach the emedical tracking sheet . Many students have reported it to be infact faster than the online application. All the best!