Add more options to the tool

[leberwurstsaft]

Hi, I felt the need to add some options to the tool to simply turn nightshift off/on without changing the strength.

Also, since the my reason for using the tool in the first place was that I have a little problem with NightShift and an external display that displays warmer tones after waking my MacBook (despite not actually being supported by NightShift anyway) and the only fix for that is to cycle NightShift to "on" and back to "off", I added a "reset" option as well, which does just that. Put it on a keyboard shortcut and am happy again :)