Dropping package facades:

- light classes: do not generate light class for package facade
- drop package facades as multifile classes compilation mode support
- get rid of some additional package facade fqName usages
- update tests for light classes

idea/testData/findUsages/kotlin/findFunctionUsages/kotlinTopLevelMethodUsages.2.java

@@ -1,11 +1,11 @@
 package client;
 
-import server.ServerPackage;
+import server.KotlintopLevelMethodUsages_0Kt;
 
 class JClient {
-    String s = ServerPackage.processRequest();
+    String s = KotlintopLevelMethodUsages_0Kt.processRequest();
 
     String sendRequest() {
-        return ServerPackage.processRequest();
+        return KotlintopLevelMethodUsages_0Kt.processRequest();
     }
 }

idea/testData/findUsages/kotlin/findFunctionUsages/kotlinTopLevelMethodUsages.3.java

@@ -1,11 +0,0 @@
-package client;
-
-import server.KotlinTopLevelMethodUsages_0Kt;
-
-class JClient {
-    String s = KotlinTopLevelMethodUsages_0Kt.processRequest();
-
-    String sendRequest() {
-        return KotlinTopLevelMethodUsages_0Kt.processRequest();
-    }
-}