Use Jackson TokenBuffer in JsonDecoder

The JsonDecoder implements a class for replaying parts of the JSON stream when accessing fields out of order.

This module can take advantage of TokenBuffers to reduce code size. This buffer can be read back as a parser.

https://github.com/apache/avro/blob/db992cf8686ffa681b0c592696b37ad519c33ee6/lang/java/avro/src/main/java/org/apache/avro/io/JsonDecoder.java#L514-L754