feat(ios,android,web): add option to allow auto-correction away from valid words in predictive text 🚂

> One long-time pet peeve of mine when it comes to auto-correct: it should **_never_** correct away from a perfectly-valid word of the language. Even if `it's` is a more common word in English than `its`, I believe that `its` should be left in place. (I find it quite the pain on iOS, as I've had to fight iOS to leave `its` before.)

Interestingly, I've seen other users who *love* this. `its` vs `it's` is impossible to get right without some grammatical awareness of course... but in the more general case, I wonder if this should be surfaced as an option for users?

_Originally posted by @mcdurdin in https://github.com/keymanapp/keyman/issues/11876#issuecomment-2210339792_