Add quickfix for missing 'constructor' inside primary ctor

idea/testData/quickfix/migration/missingConstructorKeyword/basic.kt

@@ -0,0 +1,3 @@
+// "Add 'constructor' keyword" "true"
+
+class A private<caret>()

idea/testData/quickfix/migration/missingConstructorKeyword/basic.kt.after

@@ -0,0 +1,3 @@
+// "Add 'constructor' keyword" "true"
+
+class A private constructor()

idea/testData/quickfix/migration/missingConstructorKeyword/manyFilesMuitliple.after.data.Sample.kt

@@ -0,0 +1 @@
+class Q private constructor()

idea/testData/quickfix/migration/missingConstructorKeyword/manyFilesMuitliple.after.kt

@@ -0,0 +1,12 @@
+// "Add missing 'constructor' keyword in whole project" "true"
+
+annotation class Ann(val x: Int = 1)
+
+class A @Ann(1)private constructor(x: Int) {
+    inner class B() // do not insert here
+    inner class C        protected constructor() {
+        fun foo() {
+            @data class Local private constructor()
+        }
+    }
+}

idea/testData/quickfix/migration/missingConstructorKeyword/manyFilesMuitliple.before.Main.kt

@@ -0,0 +1,12 @@
+// "Add missing 'constructor' keyword in whole project" "true"
+
+annotation class Ann(val x: Int = 1)
+
+class A @Ann(1)<caret>private (x: Int) {
+    inner class B() // do not insert here
+    inner class C        protected                () {
+        fun foo() {
+            @data class Local private()
+        }
+    }
+}

idea/testData/quickfix/migration/missingConstructorKeyword/manyFilesMuitliple.before.data.Sample.kt

@@ -0,0 +1 @@
+class Q private()