Added 2 new constructors for FileTape which copy the size of existing tape into a new one
Implemented external sort of a Tape using heap sort
Rewritten FileTape constructors implementation to better take advantage of existing constructor calls
Added const to some parameters to indicate their immutability
Added unit tests for external_sort
Removed explicit keyword before every constructor in FileTape
Added getters for private fields in FileTape
Made Tape's copy construcot marked as delete by default
Implemented custom destrucor for FileTape
Added explicit move and copy constructors to FileTape
Added generate_tmp_file_name method to tape namespace
Removed assets directory from tests - testing data should be provided in the test's cpp file
Disabled warnings as errors
bumped the cmake min version to 3.12 for c++20 support and -j flag
Placed a CMakeLists.txt in each subdirectory of the project