[Ion] Embedded value lost when deserializing with @JsonTypeInfo

I found an issue when trying to deserialize an IonValue embedded in a pojo. The conditons I've found that are required to hit it:

1. Must be deserializing to Ion
2. Must have `@JsonTypeInfo` annotation on the class (or on a super class) that specifies the type in a property.
3. The type attribute must come after other attributes of the struct. Anything before the type attribute will be lost during deserialization.

When I've walked through this with a debugger, I found something suspicious happening at [this line](https://github.com/FasterXML/jackson-databind/blob/master/src/main/java/com/fasterxml/jackson/databind/jsontype/impl/AsPropertyTypeDeserializer.java#L125). I found it was creating a sequence of a json and ion parser and started using the json parser once the type was identified.

This may be related to https://github.com/FasterXML/jackson-dataformats-binary/issues/149 .

Code to reproduce:

```java
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import software.amazon.ion.IonSystem;
import software.amazon.ion.IonValue;
import com.fasterxml.jackson.dataformat.ion.ionvalue.IonValueMapper;
import software.amazon.ion.system.IonSystemBuilder;

@JsonTypeInfo(
use = JsonTypeInfo.Id.NAME,
property = "type")
public class Main {
private IonValue value;

@JsonCreator
public Main(@JsonProperty("value") IonValue value) {
this.value = value;
}

public IonValue getValue() {
return value;
}

public static void main(String[] args) throws Exception{
IonSystem system = IonSystemBuilder.standard().build();
IonValueMapper mapper = new IonValueMapper(system);

Main main = mapper.parse(system.singleValue("{value:4.0, type: \"Main\"}"), Main.class);
System.out.println("newMain value: " + main.getValue()); // prints null, but should be 4.0.
}
}
```

Tested with the following dependencies:

```xml


com.fasterxml.jackson.dataformat
jackson-dataformat-ion
2.9.7


software.amazon.ion
ion-java
1.2.0


com.fasterxml.jackson.core
jackson-core
2.9.7


com.fasterxml.jackson.core
jackson-databind
2.9.7


com.fasterxml.jackson.core
jackson-annotations
2.9.7

```