Remove `inner` classes

Language Design
1

Instead of inner classes. Make it so inner classes go inside the base of classes, and static classes go in companion objects. Besides breaking compatibility with lots of code, I see no reason why this isn’t a good idea. It makes more sense with how Kotlin companion objects work.

class Test {
  val thing = "Hi"

  class Inner {
    init {
      print(thing)
    }
  }

  companion object {
    class StaticClass {
      init {
        print(thing) // Error!
      }
    }
  }
}