New button in 'Sampling' -> 'Database Actions' that allows the user to clean the local database. If this button is pressed, it confirms that the user what's to clear the database. A backup copy is saved in the external storage: /storage/emulated/0/FieldDay/archive/<date>-readings.db, and all of the local tables are dropped and re-created. These methods are also called upon successfully uploaded tables to the remote database.