Introduce inspection detecting self-assignment of properties

So #KT-20714 Fixed

idea/testData/inspectionsLocal/selfAssignment/withReceiver.kt

@@ -0,0 +1,7 @@
+// PROBLEM: none
+
+class Point(var x: Int) {
+    fun copyFrom(other: Point) {
+        x = <caret>other.x
+    }
+}