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

docs/cmdline-opts/Makefile.inc

@@ -265,6 +265,7 @@ DPAGES = \
   tlsv1.d \
   tr-encoding.d \
   trace-ascii.d \
+  trace-ids.d \
   trace-time.d \
   trace.d \
   unix-socket.d \

docs/cmdline-opts/trace-ids.d

@@ -0,0 +1,12 @@
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Long: trace-ids
+Help: Add transfer and connection identifiers to trace/verbose output
+Added: 8.2.0
+Category: verbose
+Example: --trace-ids --trace-ascii output $URL
+See-also: trace verbose
+Multi: boolean
+Scope: global
+---
+Prepends the transfer and connection identifiers to each trace or verbose line that curl displays.

docs/cmdline-opts/trace.d

@@ -7,7 +7,7 @@ Mutexed: verbose trace-ascii
 Category: verbose
 Example: --trace log.txt $URL
 Added: 7.9.7
-See-also: trace-ascii trace-time
+See-also: trace-ascii trace-ids trace-time
 Multi: single
 Scope: global
 ---