[BUG]: scalar output is None pytables error #707
Description
Describe the bug
During the school, students ran into issues where the mt_history_XXXX was empty due to only evolving part of the evolution. Since we set these parameters to None at BinaryStar and SingleStar initialisation, this causes issues when the binary is written to the file. We should handle these in the "cleaning" of the output data before writing it to the file.