Replace org.json usage with kotlinx.serialization

[Doomsdayrs]

Is your feature request related to a problem? Please describe.
Currently the code base uses org.json to handle serialization / de-serialization of JSON objects. This is quite outdated and clunky of a technique when compared to the kotlinx.serialization method.

Describe the solution you'd like
Simplify JSON code base using kotlinx.serialization

• https://github.com/Kotlin/kotlinx.serialization
• https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/basic-serialization.md