Tests: Add case for -Wdev and -Wno-dev with non-message() warnings (#15747)

Tests/RunCMake/CommandLine/Wdev-stderr.txt

@@ -2,4 +2,10 @@
   Some Author Warning
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+CMake Warning \(dev\) at Wdev.cmake:6 \(include\):
+  include\(\) given empty file name \(ignored\).
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
 This warning is for project developers.  Use -Wno-dev to suppress it.$

Tests/RunCMake/CommandLine/Wdev.cmake

@@ -1 +1,6 @@
 message(AUTHOR_WARNING "Some Author Warning")
+
+# with -Wdev this will also cause an AUTHOR_WARNING message, checks that
+# messages issued outside of the message command, by other CMake commands, also
+# are affected by -Wdev
+include("")

Tests/RunCMake/CommandLine/Wno-dev.cmake

@@ -1 +1,6 @@
 message(AUTHOR_WARNING "Some Author Warning")
+
+# without -Wno-dev this will also cause an AUTHOR_WARNING message, checks that
+# messages issued outside of the message command, by other CMake commands, also
+# are affected by -Wno-dev
+include("")