Fix unit tests actions for frontend

[dariogmori]

The github actions are currently broken and they need fixing for the frontend application. (For reference see the actions run in #64 or #65)

[jjgancfer]

Regarding #64, the working code is nearly finished and expected to be working tomorrow. Regarding #65, #64 had the same problem and I worked out how to solve it (it may be more of a work-around than a true solution, but for now it will do). Please, check out this commit for a solution. If @sergiorodriguezgarcia does not mind, I should be able to solve it (at least the common part) myself tomorrow.

[sergiorodriguezgarcia]

I have no problem with you doing the common part @jjgancfer. As soon as you finish that part, let me know and I will continue with it

[jjgancfer]

@sergiorodriguezgarcia has solved the problem on his own, but the tests are currently not working due to what seems to be a dependency problem.

Regarding the login, there has been a unexpected, possibly-CORS-related problem. See #69 for more information.