generic performance ideas issue

[marcustyphoon]

• Cache gear stats that were not relevant (see: https://discord.com/channels/301270513093967872/842629146857177098/858132195701293101)
• Cache a bunch of _testCharacter calls and run them in a web worker
• Preprocess flat modifiers into settings.baseAttributes during setup; replace preConversionAttributes unnecessary object clone with referencing baseattributes, preprocess additive mods into multiplicative ones, stop storing multipliers as arrays of length 1
• cache the results of post-conversion [condition damage, expertise] => condition portion of damage, as I don't see any way for that not to have the same result