Change BPM on Prime 4 unit

Would really love this feature on the P4! So you can re-adjust the BPM from false analyzing on the fly with the mighty machine itself! This can also be necessary/ helpful with tidal tracks which have incorrect BPM data after analycing!

BTW: Rekordbox nor Serato never did the full job on BPMs! So if Engine Prime gets an update it also should do a step further in this BPM story!