build: boost, prevent use of std::unary_function (#640)

* build: boost, prevent use of std::unary_function

For Boost 1.72 we should use -D_HAS_AUTO_PTR_ETC=0, for newer versions
-DBOOST_NO_CXX98_FUNCTION_BASE.

- boostorg/container_hash@fd310d2
- boostorg/functional@6a573e4
- bitcoin/bitcoin@880d4aa
- bitcoin/bitcoin@d4c59da
- DeckerSU/KomodoOcean@0742048

This will remove warnings like the one shown below during build with GCC 13:

```
/home/decker/komodo/depends/x86_64-unknown-linux-gnu/share/../include/boost/container_hash/hash.hpp:130:33: warning: ‘template<class _Arg, class _Result> struct std::unary_function’ is deprecated [-Wdeprecated-declarations]
  130 |         struct hash_base : std::unary_function<T, std::size_t> {};
      |                                 ^~~~~~~~~~~~~~
In file included from /usr/include/c++/13/string:49,
                 from /usr/include/c++/13/bits/locale_classes.h:40,
                 from /usr/include/c++/13/bits/ios_base.h:41,
                 from /usr/include/c++/13/ios:44,
                 from /usr/include/c++/13/ostream:40,
                 from /home/decker/komodo/depends/x86_64-unknown-linux-gnu/share/../include/gtest/gtest.h:55,
                 from test-komodo/test_legacy_events.cpp:1:
/usr/include/c++/13/bits/stl_function.h:117:12: note: declared here
  117 |     struct unary_function
      |            ^~~~~~~~~~~~~~
```

* build: add BOOST_CPPFLAGS display for configure

configure.ac

@@ -629,6 +629,16 @@ AX_BOOST_PROGRAM_OPTIONS
 AX_BOOST_THREAD
 AX_BOOST_CHRONO
 
+dnl Prevent use of std::unary_function, which was removed in C++17,
+dnl and will generate warnings with newer compilers for Boost
+dnl older than 1.80.
+dnl See: https://github.com/boostorg/container_hash/issues/22, https://github.com/boostorg/config/pull/430.
+
+dnl _HAS_AUTO_PTR_ETC check required only for boost 1.72 and older, since 1.73 we can use BOOST_NO_CXX98_FUNCTION_BASE
+AX_CHECK_PREPROC_FLAG([-D_HAS_AUTO_PTR_ETC=0], [BOOST_CPPFLAGS="$BOOST_CPPFLAGS -D_HAS_AUTO_PTR_ETC=0"], [], [$CXXFLAG_WERROR],
+                      [AC_LANG_PROGRAM([[#include <boost/config.hpp>]])])
+AX_CHECK_PREPROC_FLAG([-DBOOST_NO_CXX98_FUNCTION_BASE], [BOOST_CPPFLAGS="$BOOST_CPPFLAGS -DBOOST_NO_CXX98_FUNCTION_BASE"], [], [$CXXFLAG_WERROR],
+                      [AC_LANG_PROGRAM([[#include <boost/config.hpp>]])])
 fi
 
 if test x$use_reduce_exports = xyes; then
@@ -933,21 +943,22 @@ esac
 
 echo 
 echo "Options used to compile and link:"
-echo "  with wallet   = $enable_wallet"
-echo "  with proton   = $use_proton"
-echo "  with zmq      = $use_zmq"
-echo "  with test     = $use_tests"
-echo "  debug enabled = $enable_debug"
-echo "  werror        = $enable_werror"
+echo "  with wallet    = $enable_wallet"
+echo "  with proton    = $use_proton"
+echo "  with zmq       = $use_zmq"
+echo "  with test      = $use_tests"
+echo "  debug enabled  = $enable_debug"
+echo "  werror         = $enable_werror"
 echo 
-echo "  target os     = $TARGET_OS"
-echo "  build os      = $BUILD_OS"
+echo "  target os      = $TARGET_OS"
+echo "  build os       = $BUILD_OS"
 echo
-echo "  CC            = $CC"
-echo "  CFLAGS        = $CFLAGS"
-echo "  CPPFLAGS      = $CPPFLAGS"
-echo "  CXX           = $CXX"
-echo "  CXXFLAGS      = $CXXFLAGS"
-echo "  LDFLAGS       = $LDFLAGS"
-echo "  ARFLAGS       = $ARFLAGS"
+echo "  CC             = $CC"
+echo "  CFLAGS         = $CFLAGS"
+echo "  CPPFLAGS       = $CPPFLAGS"
+echo "  CXX            = $CXX"
+echo "  CXXFLAGS       = $CXXFLAGS"
+echo "  BOOST_CPPFLAGS = $BOOST_CPPFLAGS"
+echo "  LDFLAGS        = $LDFLAGS"
+echo "  ARFLAGS        = $ARFLAGS"
 echo