Rename NamingStrategy to FieldNamingStrategy

[Chuckame]

Current issue

Now, defining a naming strategy impacts both records' and fields' name... Well it seems. It only applies the naming strategy to field names (and the fixed names as it relies on the field name).

Proposal

Have a clear FieldNamingStrategy and improve the interface:

public interface FieldNamingStrategy {
    public fun resolve(
        descriptor: SerialDescriptor,
        elementIndex: Int,
    ): String

    public companion object Builtins {
        public object NoOp : FieldNamingStrategy {
            override fun resolve(
                descriptor: SerialDescriptor,
                elementIndex: Int,
            ): String = descriptor.getElementName(elementIndex)
        }

        public object SnakeCase : FieldNamingStrategy {
                // ...
        }

        public object PascalCase : {
                // ...
        }
    }
}

[Chuckame]

Done in #182

[Chuckame]

open it back, waiting for a real release