raidboss: Fix ParseHelperType definitions

[valarnin]

To quote Discord DMs:

valarnin: ... is it just me, or is the ParseHelperType in netregexes.ts just flat out incorrectly defined? I just have no clue how typescript allows it in its current state.
Consider:

type ParseHelperType<T extends LogDefinitionTypes> =
  & {
    [field in Extract<keyof NetFieldsReverse[T], string>]?: string;
  }
  & { capture?: boolean };

type EmptyType = ParseHelperType<'Ability'>;

type ParseHelperTypeFixed<T extends LogDefinitionTypes> =
  & {
    [field in keyof NetFields[T]]?: string | string[];
  }
  & { capture?: boolean };

type CorrectType = ParseHelperTypeFixed<'Ability'>;

valarnin: (in fact, Extract<keyof NetFieldsReverse[T], string> evaluates to never because all keys of a given NetFieldsReverse type entry are numerical and therefore can never be assigned to string)

[quisquous]

How did this even work??

[valarnin]

How did this even work??

At a guess, the narrowing to never made typescript shrug and say "they probably know what they're doing", but honestly I have no clue. Or maybe it's because the parent types are pulled from a .d.ts file which is evaluated/scoped differently.