Show schedules with no professors

[Process-ing]

Currently, there is a problem in Sigarra with classes that have no professors assigned. Basically, they give a professor compost without professors. For example, see https://sigarra.up.pt/feup/pt/hor_geral.turmas_view?pv_turma_id=213191&pv_periodos=2&pv_ano_lectivo=2023 , AED class on thursday.

They are being properly scrapped, but the planner ignores those practical classes and does not let them being selected (which has the benefit of not breaking the planner, since the current structure does not allow schedules without professors). The objective is to allow the planner to show those classes without any professor information, like this: