Parallelize Coverage files creation

[gabriel-aranha-cw]

Currently we have one command that runs all E2E tests and uploads a single coverage file. This action takes a long time(50 minutes), which makes it difficult to debug and fix broken tests. By separating the coverage creation and leaving Codecov to do the merging, the total time to run coverage should improve.

[carneiro-cw]

Possibly we can use the already existing test actions and add some codecov hook to the end of each action. Codecov merges those coverages (I think :p)