feat: Use kotlinx-serialization

[oSumAtrIX]

Feature description

Use Kotlinx-serialization instead of Gson with Patcher v20

Motivation

Gson was used for the utility serialization functions, but with Patcher v20, this won't be necessary anymore since options of patches store the type of generic type parameters, which can be used for reflectionless serialization

Acknowledgements

• [X] This issue is not a duplicate of an existing feature request.
• [X] I have chosen an appropriate title.
• [X] All requested information has been provided properly.