Move around some codegen box tests

In tests merged from boxAgainstJava in 29b96aa1, some directories were
named slightly differently compared to box, e.g. "property" vs
"properties", "varargs" vs "vararg". This change renames these, moves
some of the tests to more fitting directories, and also renames
"visibility" to "javaVisibility" because it's about Java visibilities
specifically.

compiler/testData/codegen/box/enum/javaClassWithNestedEnum.kt

@@ -0,0 +1,20 @@
+// TARGET_BACKEND: JVM
+// MODULE: lib
+// FILE: test/JavaClass.java
+
+package test;
+
+public class JavaClass {
+    public enum E { ENTRY }
+    
+    public static String foo() { return "OK"; }
+}
+
+// MODULE: main(lib)
+// FILE: 1.kt
+
+package test
+
+fun box(): String {
+    return JavaClass.foo()!!
+}