Quality of life changes

Added setting(clap::AppSettings::SubcommandRequiredElseHelp) to print help messages for invalid commands.
Updated all API call functions (login, enqueue, status, and cancel) to provide more detailed error messages and raw server responses.
Renamed --override-timeout to --timeout
Improved logging in most places

SSH key handling:

Implemented a new read_ssh_keys function reads from: a. SSH agent b. Public key files in the user's .ssh directory c. Config file