Local prediction: Clean progress bar for multi-threaded prediction

[JSchlensok]

Is your feature request related to a problem? Please describe.
Currently, when using multiple threads for local prediction, the progress bars of each thread's predictor (default DLomix/Keras inference progress bar) glitch and overlap in stdout, greatly decreasing readability.

Describe the solution you would like
Cleaner and more informative progress bar, either by separating them for every thread, or doing one big progress bar over all threads' batches.