[REQ] Add deserializers in generated kotlin models

Created by: kentis

Is your feature request related to a problem? Please describe.

Deserializing JSON objects with Jackon, by default, uses reflection. All the information about how to deserialize an object is availbale in the OpenAPI spec. This leads to perfomance issues since reflection is a lot slower than explicitly compiled code. In projects that handle large amounts of JSON data this can become a significant bottleneck when processing.

Describe the solution you'd like

We propose to generate Deserializers when generating Kotlin data classes for a model when using the Jackson library. This allows parsing JSON objects using explicitly compiled code rather than relying on reflection. Experiments show that this achives an approximate 3x speedup of JSON parsing.

Describe alternatives you've considered

We looked at the Afterburner module in Jackson, but this does not utilize the information available in the OpenAPI spec and thus does not give the wanted performance boost.