Use VSS Gradle Plugin / Task in favour of KSP for generating VSS models

[Chrylo]

Is your feature request related to a problem? Please describe.
The project currently uses Kotlins Symbol Processing (Annotation processing) for generating all necessary Kotlin models from the VSS definition file. With the changes of #45 we may remove the KSP dependency completely and generate everything inside the custom VSS Plugin.

Describe the solution you'd like

• Move the generation code to the VSS Plugin module
• Remove all KSP dependencies
• Use Input / Output annotation caching with custom tasks so that all classes are not re-generated if not necessary