incorporate starter values correctly when calculating totals

[paul-c-guest]

total wet content is calculated with a simple accumulator, and does not take into account that the starter is commonly kept at a different hydration ratio (e.g. 100%).

the 'total wet' amount is likely to then be misleading (and making incorrectly hydrated dough), and should be modulated by the expected hydration of the starter flour

[paul-c-guest]

partially working, now need to make changes to 'liquid to add' when dry starter amount changes

[paul-c-guest]

fixed bad math in totals.tsx, totals are now behaving as expected, i.e. hydration is calculated correctly regardless of starter hydration beign default or any other value