Introduce Property: Initial support (properties with getter)

idea/testData/refactoring/introduceProperty/extractWithGetterToFile.kt.after

@@ -0,0 +1,11 @@
+// EXTRACTION_TARGET: property with getter
+val n: Int = 1
+
+fun foo(): Int {
+    return i
+}
+
+private val i: Int
+    get() {
+        return n + 1
+    }