Drops specified keys from an association; supports the operator form KeyDrop[keys][assoc]
KeyDrop[assoc, {key1, key2, …}]
KeyDrop[{assoc1, assoc2, …}, keys]
KeyDrop[keys]
KeyDrop[<|a -> 1, b -> 2, c -> 3|>, {a}]
→ <|b -> 2, c -> 3|>KeyDrop[{b}][<|a -> 1, b -> 2, c -> 3|>]
→ <|a -> 1, c -> 3|>