MC hit time converter (from JTE)

This is also needed, to convert MC times (of hits) to JTE times.

See TimeSorter in km3io: https://git.km3net.de/km3py/km3io/-/blob/b71300ff1364394d01323a732585f0a8dae303b1/src/km3io/tools.py#L595

added easy enhancement labels