Change "casted" to "cast" through this repo

[john-light]

The past tense of "cast" as in "cast a vote" is "cast", not "casted". The phrase "casted" still appears multiple times throughout this repo.

e.g.

uint256 optionsCastedLength;

[sohkai]

Closing and placing in #1101.

All the frontends have been fixed—the only remaining places where this is still the case is in contracts, and those are usually not presented to the user :).