Implement new command system

[rainybreeze777]

Replace the old command system with Key listener in order to be able to press down keys and trigger commands instead of typing

[rainybreeze777]

Research documentation: Please note that we are using KeyListener class from javax.awt. This class, however, is bound with Swing classes, so it does NOT work separately with commandlines; we are forced to write the graphics first, before key event systems can be replaced