Expand Effect System with receiver values (#KT-28672)

Add some classes to hierarchy of `ESValue`:
- `ESReceiver` -- representation of receiver
  of lambda function
- `ESDataFlow` and `ESDataFlowReceiver` -- little refactoring of entities
  that holds information for DFA (description in comments in code).

Also add kdoc to classes of `ESValue` hierarchy

compiler/testData/diagnostics/testsWithStdLib/contracts/smartcasts/extensionReceiver.kt

@@ -20,7 +20,7 @@ fun smartcastOnReceiver(s: String?) {
             <!UNSAFE_CALL!>length<!>
         }
         else {
-            <!UNSAFE_CALL!>length<!>
+            <!DEBUG_INFO_IMPLICIT_RECEIVER_SMARTCAST!>length<!>
         }
     }
 }