tool: add curl command line option --trace-ids

- added and documented --trace-ids to prepend (after the timestamp)
  the transfer and connection identifiers to each verbose log line
- format is [n-m] with `n` being the transfer id and `m` being the
  connection id. In case there is not valid connection id, print 'x'.
- Log calls with a handle that has no transfer id yet, are written
  without any ids.

Closes #11185

src/tool_getparam.c

@@ -205,6 +205,7 @@ static const struct LongShort aliases[]= {
   {"$Z", "compressed-ssh",           ARG_BOOL},
   {"$~", "happy-eyeballs-timeout-ms", ARG_STRING},
   {"$!", "retry-all-errors",         ARG_BOOL},
+  {"$%", "trace-ids",                ARG_BOOL},
   {"0",   "http1.0",                 ARG_NONE},
   {"01",  "http1.1",                 ARG_NONE},
   {"02",  "http2",                   ARG_NONE},
@@ -1407,6 +1408,9 @@ ParameterError getparameter(const char *flag, /* f or -long-flag */
           return err;
         /* 0 is a valid value for this timeout */
         break;
+      case '%': /* --trace-ids */
+        global->traceids = toggle;
+        break;
       }
       break;
     case '#':