Log detailed correlated consensus data together (#5302)

Combine multiple related debug log data points into a single
message. Allows quick correlation of events that
previously were either not logged or, if logged, strewn
across multiple lines, making correlation difficult.
The Heartbeat Timer and consensus ledger accept processing
each have this capability.

Also guarantees that log entries will be written if the
node is a validator, regardless of log severity level.
Otherwise, the level of these messages is at INFO severity.

include/xrpl/basics/Log.h

@@ -67,6 +67,10 @@ private:
         void
         write(beast::severities::Severity level, std::string const& text)
             override;
+
+        void
+        writeAlways(beast::severities::Severity level, std::string const& text)
+            override;
     };
 
     /** Manages a system file containing logged output.
@@ -256,6 +260,14 @@ private:
         x
 #endif
 
+#ifndef CLOG
+#define CLOG(ss) \
+    if (!ss)     \
+        ;        \
+    else         \
+        *ss
+#endif
+
 //------------------------------------------------------------------------------
 // Debug logging: