fix: conflicting where inputs

[davenewza]

There is no need to restrict a field which is filtered by inputs and in @where. See example schema below where this case would be valid. This PR relaxes that condition, but we still validate against using write values and @set on the same field.

model Order {
    fields {
	quantity Number
	price Decimal
	category Text
	status Status
    }
    actions {
	list listOrders(status?, category?) {
            @where(order.status != Status.Cancelled)
	}
    }
}