Add quickfix for adding 'lateinit'

Fixes #KT-17650

idea/testData/quickfix/modifiers/addLateinit.kt

@@ -0,0 +1,5 @@
+// "Add 'lateinit' modifier" "true"
+
+class A {
+    private var a: String<caret>
+}

idea/testData/quickfix/modifiers/addLateinit.kt.after

@@ -0,0 +1,5 @@
+// "Add 'lateinit' modifier" "true"
+
+class A {
+    private lateinit var a: String<caret>
+}

idea/testData/quickfix/modifiers/noLateinitOnNullable.kt

@@ -0,0 +1,10 @@
+// "Add 'lateinit' modifier" "false"
+// ACTION: Add initializer
+// ACTION: Make 'a' abstract
+// ACTION: Move to constructor parameters
+// ACTION: Move to constructor
+// ERROR: Property must be initialized or be abstract
+
+class A {
+    private var a: String?<caret>
+}

idea/testData/quickfix/modifiers/noLateinitOnPrimitive.kt

@@ -0,0 +1,10 @@
+// "Add 'lateinit' modifier" "false"
+// ACTION: Add initializer
+// ACTION: Make 'a' abstract
+// ACTION: Move to constructor parameters
+// ACTION: Move to constructor
+// ERROR: Property must be initialized or be abstract
+
+class A {
+    private var a: Int<caret>
+}