Add inspection for suspicious 'var' property #KT-23691 Fixed

idea/testData/inspectionsLocal/suspiciousVarProperty/hasBackingFieldRef2.kt

@@ -0,0 +1,7 @@
+// PROBLEM: none
+class Test {
+    <caret>var foo: Int = 0
+        get() {
+            return field
+        }
+}