suppress cppcheck issues in Testing/Cxx so we can focus on impl

cppcheck warnings in tests are hiding implementation issues.
For now turn of cppcheck issues in the test code so we can
focus on any issues in the VTK implementation code.

CMake/VTKcppcheckSuppressions.txt

@@ -34,6 +34,14 @@
 // If cppcheck itself crashes, well, that's its problem, ignore that.
 cppcheckError
 
+// Tests contain lots of hardcoded values, etc. They overwhelm reporting of issues
+// in the implementation files. So for now suppress the test's issues so we can focus
+// on implementation issues
+constArgument:*/Testing/Cxx/*
+duplicateCondition:*/Testing/Cxx/*
+knownConditionTrueFalse:*/Testing/Cxx/*
+unreadVariable:*/Testing/Cxx/*
+
 // When analyzing different define possibilities, it will sometimes hit a #error line
 preprocessorErrorDirective