Generate classes in MultifileClassCodegen exactly the same as in PackageCodegen

Two known issues with generateNonPartClassDeclarations that was here
before were the fact that we didn't sort sealed classes and its
subclasses which led to NoSuchMethodError (KT-27097), and the fact that
we didn't skip expect classes which led to incorrect duplicate JVM class
name diagnostic (KT-30843)

 #KT-27097 Fixed
 #KT-30843 Fixed

compiler/testData/codegen/box/multifileClasses/sealedClassHierarchy.kt

@@ -0,0 +1,13 @@
+// IGNORE_BACKEND: JVM_IR
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+@file:JvmMultifileClass
+@file:JvmName("Test")
+package test
+
+sealed class Foo(val value: String)
+
+class Bar : Foo("OK")
+
+fun box(): String = Bar().value