Back `Nbt*Array`s with `List`s, and encode arrays as `NbtList` by default, and require `@NbtArray`

[BenWoodworth]

• Encourages using List instead of Array types (generally a good practice in Kotlin)
• Allows Arrays to be serialized as NbtLists more easily
  • currently required a custom serializer
  • would otherwise require more machinery to support
• Lets Nbt*Array types be constructed from lists
  • currently, wrapping lists in NbtArrays was not possible and required copying to new arrays
  • still supports arrays, just with e.g. NbtIntArray(intArray.asList())