Introduce replacement for getting and setting thread name: (#4312)

* In namespace ripple, introduces get_name function that takes a
  std:🧵:native_handle_type and returns a std::string.
* In namespace ripple, introduces get_name function that takes a
  std::thread or std::jthread and returns a std::string.
* In namespace ripple::this_thread, introduces get_name function
  that takes no parameters and returns the name of the current
  thread as a std::string.
* In namespace ripple::this_thread, introduces set_name function
  that takes a std::string_view and sets the name of the current
  thread.
* Intended to replace the beast utilities setCurrentThreadName
  and getCurrentThreadName.

src/test/overlay/short_read_test.cpp

@@ -17,8 +17,8 @@
 */
 //==============================================================================
 
+#include <ripple/basics/ThreadUtilities.h>
 #include <ripple/basics/make_SSLContext.h>
-#include <ripple/beast/core/CurrentThreadName.h>
 #include <ripple/beast/unit_test.h>
 #include <test/jtx/envconfig.h>
 
@@ -630,7 +630,7 @@ public:
     short_read_test()
         : work_(io_context_.get_executor())
         , thread_(std::thread([this]() {
-            beast::setCurrentThreadName("io_context");
+            this_thread::set_name("io_context");
             this->io_context_.run();
         }))
         , context_(make_SSLContext(""))