Added new face: Pomodoro Timer

[Alfedi]

Based on the legacy Tomato face and in the Countdown face, I made a simple pomodoro timer with pause, reset, and the possibility to change the timers between a given set of times.

[Alfedi]

I just realize that I left some things undone, like the low energy behaviour and the cleaning of the code. Marking this as draft and I will try to get things done as soon as I can.

[Alfedi]

Now I believe it's completed. Waiting for review :)

[voloved]

Now I believe it's completed. Waiting for review :)

I looked over the main code and it looks fine to me.
Have you had any issues with it or anything else before I pull it in?

[Alfedi]

No, I have been using it in my sensorwatch without any problem.

[voloved]

@Alfedi ,

Can you fix this warning?

watch-faces/complication/pomodoro_face.c: In function '_pomodoro_face_update_lcd':
watch-faces/complication/pomodoro_face.c:84:29: warning: '%02d' directive writing between 2 and 3 bytes into a region of size between 1 and 3 [-Wformat-overflow=]
watch-faces/complication/pomodoro_face.c:84:20: note: directive argument in the range [0, 255]
watch-faces/complication/pomodoro_face.c:84:5: note: 'sprintf' output between 7 and 10 bytes into a destination of size 7

[Alfedi]

Finally had time to check this. Warning should be fixed now.