feat(ux): include type of bad value in SignatureValidationError

[NickCrews]

While trying to do some refactoring in ibis, I was getting

SignatureValidationError: ArrayContains(┏━━━━━━━━━━━━━━━━┓
┃ arr            ┃
┡━━━━━━━━━━━━━━━━┩
│ array<int64>   │
├────────────────┤
│ [1, 2, ... +1] │
│ [2, 3, ... +1] │
└────────────────┘, _.x) has failed due to the following errors:
  `other`: _.x is not coercible to a Value

Expected signature: ArrayContains(arg: Value[Array, DataShape], other: Value)

and this was very confusign to me, because it looks like _.x is a Deferred, which should be coercible. But actually it was a deferred.BinaryOperator. Now this actually will show this in the error message, making it easier to debug.