[Boardcore] Move all old files into 'old_examples' and compile everything else

* All target files that compile without errors are added as targets; the other ones are moved in subfolders 'old_examples' and listed as comments in CMakeLists.txt.

* All source files and related header files that are used and compile without errors are added as source files; the other ones are moved in subfolders 'old_examples' and listed as comments in boardcore.cmake.

* All targets in CMakeLists.txt and sources in boardcore.cmake are listed in alphabetical order.