table: reorganize PIT implementation

Merge pit-{face,in,out}-record.{cpp,hpp} into pit-entry.{cpp,hpp}
and merge pit-iterator.{cpp,hpp} into pit.{cpp,hpp}.

Rename get{In,Out}Record() to find{In,Out}Record(), following the
typical C++ pattern of using the verb "find" for functions that
return iterators.

No functional changes.

Change-Id: I6740dd6cfe92ca477938ab8dc2f6271fd8b6cc26
diff --git a/daemon/fw/process-nack-traits.cpp b/daemon/fw/process-nack-traits.cpp
index 25b2526..6919268 100644
--- a/daemon/fw/process-nack-traits.cpp
+++ b/daemon/fw/process-nack-traits.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2023,  Regents of the University of California,
+ * Copyright (c) 2014-2024,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -55,7 +55,7 @@
 
   if (nOutRecordsNotNacked == 1) {
     BOOST_ASSERT(lastFaceNotNacked != nullptr);
-    auto inR = pitEntry->getInRecord(*lastFaceNotNacked);
+    auto inR = pitEntry->findInRecord(*lastFaceNotNacked);
     if (inR != pitEntry->in_end()) {
       // one out-record not Nacked, which is also a downstream
       NFD_LOG_NACK_FROM(nack, inFace.getId(), "bidirectional nack-to=" << lastFaceNotNacked->getId()