Fix self hit damage conversion

[Regisle]

Fixes #7190 and issue created by normalisation, and taken as not applying to non-phys self hits

Fixes taken as being only from phys to something else (present from creation), not any ele to other, as well as normalisation being applied to the taken as (fixed for calc defence in #6844 but not this), and it only including generic and not hit specific taken as (introduced issue in #6803)

This also moves the function to calc defence and cleans it up a little

I would like to properly dedupe it with other calc defence stuff (eg takenHitFromDamage) as it likely has other issues with being out of date, but it is too much work for how much time I have for it at the moment and this is still an improvement.