Fix Bio magnet description and on-hit messages

[Fris0uman]

Summary

SUMMARY: Bugfixes "Fix Bio magnet description and on-hit messages"

Purpose of change

Fixes #29745, fix Bio magnet description and on-hit messages:

• When hitting an enemy using the magnet you get a log message
• Description of the CBM does say that your own strength is involved in the process

Describe the solution

• add proper argument to projectile_attack
• edit description

Describe alternatives you've considered

Replace the useage of weight_capacitywith an hardcoded value, it doesn't make muc hsens for the weight of object the magnet can affect to depend on your weight_capacity

Following that ref http://www.walkermagnet.com/scrap-magnets-liftmaster-lm-cast-series.htm used in #34456 the cap could be 544 kg. But the smaller magnet in that link is 122cm in diameter and weight about 1225 kg (if my convertions from imperial are correct) so it's doubtfull something like this could fit in a hand.

Alternatively we could compute the strength of the magnet from the power draw.

Testing

Additional context