Do not return nested/local classes as a part of package fragment

#KT-13757 Fixed

compiler/testData/compileKotlinAgainstCustomBinaries/prohibitNestedClassesByDollarName/library/test/JavaOuter.java

@@ -0,0 +1,5 @@
+package test;
+
+public class JavaOuter {
+    public static class JavaNested {}
+}

compiler/testData/compileKotlinAgainstCustomBinaries/prohibitNestedClassesByDollarName/library/test/Outer.kt

@@ -0,0 +1,5 @@
+package test
+
+class Outer {
+    class Nested
+}

compiler/testData/compileKotlinAgainstCustomBinaries/prohibitNestedClassesByDollarName/main.kt

@@ -0,0 +1,10 @@
+import test.Outer
+import test.JavaOuter
+
+fun main(args: Array<String>) {
+    Outer.Nested()
+    test.`Outer$Nested`()
+
+    JavaOuter.JavaNested()
+    test.`JavaOuter$JavaNested`()
+}

compiler/testData/compileKotlinAgainstCustomBinaries/prohibitNestedClassesByDollarName/output.txt

@@ -0,0 +1,7 @@
+compiler/testData/compileKotlinAgainstCustomBinaries/prohibitNestedClassesByDollarName/main.kt:6:10: error: unresolved reference: `Outer$Nested`
+    test.`Outer$Nested`()
+         ^
+compiler/testData/compileKotlinAgainstCustomBinaries/prohibitNestedClassesByDollarName/main.kt:9:10: error: unresolved reference: `JavaOuter$JavaNested`
+    test.`JavaOuter$JavaNested`()
+         ^
+COMPILATION_ERROR