Added GeneralCommandType enum to IDonCommand and getGeneralType.
Implemented getGeneralType for command types that currently have an implementation. This method condenses the specific types of add/delete etc into broader types.
Added testDeleteTaskWithName and testSearchWithDate to logic tests.
Added HELP enum to CommandType. No functionality for HELP in parser yet.
Added help for add/edit/delete/search in getHelp which uses getGeneralType. No user command can make use of this method yet.