Quick-fix for header without implementation + a set of tests #KT-14908 Fixed

idea/testData/multiModuleQuickFix/class/header/header.kt

@@ -0,0 +1,15 @@
+// "Create header class implementation for platform JVM" "true"
+
+header class <caret>My {
+    fun foo(param: String): Int
+
+    fun String.bar(y: Double): Boolean
+
+    fun baz(): Unit
+
+    constructor(flag: Boolean)
+
+    val isGood: Boolean
+
+    var status: Int
+}

idea/testData/multiModuleQuickFix/class/header/header.kt.after

@@ -0,0 +1,15 @@
+// "Create header class implementation for platform JVM" "true"
+
+header class My {
+    fun foo(param: String): Int
+
+    fun String.bar(y: Double): Boolean
+
+    fun baz(): Unit
+
+    constructor(flag: Boolean)
+
+    val isGood: Boolean
+
+    var status: Int
+}

idea/testData/multiModuleQuickFix/class/jvm/my.kt

@@ -0,0 +1 @@
+// My: to be implemented

idea/testData/multiModuleQuickFix/class/jvm/my.kt.after

@@ -0,0 +1,23 @@
+// My: to be implemented
+impl class My {
+    impl fun foo(param: String): Int {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+
+    impl fun String.bar(y: Double): Boolean {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+
+    impl fun baz() {}
+
+    constructor(flag: Boolean) {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+
+    impl val isGood: Boolean
+        get() = TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    impl var status: Int
+        get() = TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+        set(value) {}
+
+}