Rename: this object, receiver argument -> dispatch receiver, extension receiver

compiler/testData/resolvedCalls/invoke/extensionReceiverAsReceiverForInvoke.txt

@@ -0,0 +1,15 @@
+class Foo
+fun Foo.invoke() {}
+
+fun bar(f: Foo) {
+    f<caret>()
+}
+
+
+Resolved call:
+
+Resulting descriptor: fun Foo.invoke(): Unit defined in root package
+
+Explicit receiver kind = EXTENSION_RECEIVER
+Dispatch receiver = NO_RECEIVER
+Extension receiver = f {Foo}