Addressing #4165 and #4166

I accidentaly pressed enter before I could write a message, so I'm detailing it here

In this pull request I attempt to address what was pointed by @paperbagcorner in #4166 and #4165, which is the cd ripper only loading information once and not really canceling afterwards.

For #4165, I've moved the cdio read check inside the `CDIOIsValid()` so it would update its info about the drive before returning it, and once it returns successful, the widget is reloaded. That all happens before the window is opened so I believe it solves the problem. This, however, doesn't solve the case in which the user switch cds with the window opened, which I couldn't figure how to detect, anyone got a clue on this?

As for #4166, pressing cancel removes the newly created temp dir, which would cause error in the subsequent calls to the files, effectively ending the execution flow. Since `QConcurrentRun` cannot be stopped and I wasn't able to quickly adapt it to a `QThread` solution, I didn't see this as a major setback, but I updated the progress bar status to 0 once cancel is clicked.