[Webserver] Display current training progress

[NikkelM]

Right now, we use tqdm to display the training progress, but unfortunately due to the way it writes to the console, we cannot display it in the webserver. It would however still be nice to know the current training progress of a container. This could for example be achieved by reading the current line of the tqdm output and displaying it somewhere separate from the logs. The same could be done by reading the current line containing the rewards and extract the current episode, since we know the total number of episodes anyways, a percentage could be calculated.