cppcheck: run checks at the package scope

By default cmake adds all the (non-system) include paths to the cppcheck command line, which causes very long processing times for some of our packages (a full build in the CI doubles from 2 to 4 hours). Add the cppcheck_atlas wrapper to remove all those -I command line arguments except for the package itself.

Use this wrapper in the Athena and WorkDir project to launch cppcheck.

The downside is that we now need to teach cppcheck about all macros used in our code base and if someone adds a new macro, which is used across package, we need to update the relevant cppcheck configuration.

Remove the suppression of the preprocessor error in CachedPointer.h and instead define the appropriate compiler variable. Not having this defined (and the error being suppressed) is one of the reasons why cppcheck was blind to a few defects in our builds (see e.g. !76484 (merged)).

Relates to ATLINFR-5443.