suricata.yaml: include version that generated this file

Add a line to the configuration that says which version generated the
configuration file.  For example:

    # This configuration generated by:
    #     Suricata 7.0.0-dev

Issue: #4784
(cherry picked from commit b5d1a80002)

suricata.yaml.in

@@ -4,6 +4,9 @@
 # Suricata configuration file. In addition to the comments describing all
 # options in this file, full documentation can be found at:
 # https://suricata.readthedocs.io/en/latest/configuration/suricata-yaml.html
+#
+# This configuration file generated by:
+#     Suricata @PACKAGE_VERSION@
 
 ##
 ## Step 1: Inform Suricata about your network