Save stripped debug symbols into same location as main binary.

The file containing the debug symbols is now saved to CMAKE_LIBRARY_OUTPUT_DIRECTORY and CMAKE_RUNTIME_OUTPUT_DIRECTORY alongside with the main stripped binaries. This allows the gdb to be run without having to install project first. A big beneficiary is using the debugging inside IDEs (ie: VSCode) that do not install projects before running them inside debugger.

Also the INSTALL line is no longer needed as all contents of build/bin and build/lib are copied during installation.