cmake: Extend qt_configure_add_summary_section by a message type

With the existing types we can only display a list of features or
whether a feature is on or off, but we cannot display arbitrary values.

Using the new message type, it is possible to show paths or versions as
summary entries.

Change-Id: I5d16cb4b30923f3566755bd4d7440bdd1ece82f5
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

cmake/QtBuildInformation.cmake

@@ -261,6 +261,8 @@ function(qt_configure_process_add_summary_entry)
         endif()
 
         qt_configure_add_report_padded("${label}" "${value}")
+    elseif(arg_TYPE STREQUAL "message")
+        qt_configure_add_report_padded("${arg_ARGS}" "${arg_MESSAGE}")
     endif()
 endfunction()