Add toString() to Any, fix all tests

#KT-4517 Fixed

idea/testData/codeInsight/overrideImplement/complexMultiOverride.kt.after

@@ -19,4 +19,7 @@ class C : Base<String, C, Unit>() {
         return super<Base>.hashCode()
     }
     override val method: (String?) -> String = ?
+    override fun toString(): String {
+        return super<Base>.toString()
+    }
 }

idea/testData/codeInsight/overrideImplement/inheritVisibilities.kt.after

@@ -30,4 +30,7 @@ class C : A(), B {
         super<A>.publicFun()
     }
     override val publicProperty: Int = 0
+    override fun toString(): String {
+        return super<A>.toString()
+    }
 }

idea/testData/codeInsight/overrideImplement/multiOverride.kt.after

@@ -17,4 +17,7 @@ class C : A {
     override fun hashCode(): Int {
         return super<A>.hashCode()
     }
+    override fun toString(): String {
+        return super<A>.toString()
+    }
 }

idea/testData/codeInsight/overrideImplement/overrideRespectCaretPosition.kt.after

@@ -16,6 +16,9 @@ class C : A() {
     override fun hashCode(): Int {
         return super<A>.hashCode()
     }
+    override fun toString(): String {
+        return super<A>.toString()
+    }
 
     /*
         Some another comment