Allow custom brew duration

[Aman7123]

This coffee pot does not allow adjusting the length of brew, it works until all the water is boiled and gone.

This ticket is to open the idea of allowing the BREW_CYCLE_TIMEOUT field to be instantiated in the main ESP8266-Coffee-Pot.ino file as an integer and allowing both POST and PATCH to update the value.

I do believe this ticket will require a rework to the brewTimeout internal variable which determines when to stop a brew and is calculated on startup, this system could move to storing the time of initial brew then constantly checking if:

systemClock > (brewInitiationTime + brewCycleLength)