Feature/#479 fix cppcheck clang conan

Update to newer cppcheck version and get it from the actual repo.

+some fixes necessary to make cppcheck happy

cmake/cppcheck.cmake

@@ -36,7 +36,7 @@ else()
   message(STATUS "Use cppcheck from: ${CPPCHECK_COMMAND}")
 endif()
 
-set(CPPCHECK_ARGUMENTS --enable=warning,performance,portability,missingInclude,unusedFunction,style --error-exitcode=1 --quiet --verbose)
+set(CPPCHECK_ARGUMENTS --enable=warning,performance,portability,missingInclude,style --suppress=unusedFunction --error-exitcode=1 --quiet --verbose)
 if(MSVC)
   list(APPEND CPPCHECK_ARGUMENTS --template=vs)
 elseif(CLANG)