Scala 3 cross-compile with removed serialization and rhttpc-akka-persistence modules

[mgoworko]

• JDK 8 -> 11
• Scala version: Scala 3.3.5/2.13.16 cross compile, dropped 2.12 support
• Serialization: removed rhttpc-json4s and rhttpc-argonaut_6.2 modules, instead relying on custom serialization impl's provided when developers use this library
• Persistance: now focused only on request/response persistance, removed Akka persistance module rhttpc-akka-persistence
• Example http client: removed module rhttpc-akka-http, this was only example and was troublesome to move to Scala 3 because of serialization