Errors passing data between fragments

[MTSS]

• original design saved osc input data into shared-prefs, then read it from the fragments.
• swapped over to using a singleton sat in the background to handle everything, but this is really struggling. i think it is something to do with the timings during saving/recalling data, it all seems to get out of sync and crash.
• i am going to revert to saving data to shared-prefs (because there isn't acually that much data being thrown around).