Add capacity measurement option

[Jakeler]

• [ ] Settings option "Measure Capacity [mAh]"
• [ ] Include accumulated cap in unit line
• [ ] Reset option, either settings or main UI
• [ ] Wh option, with const voltage?

[Alvadep]

Hi, how things are going with "Measure Capacity [mAh]"? In my opinion, everything should be very simple. Each current value obtained must be divided by 7200 and added to the capacity value. This will be the capacity value in mAh. It is also possible to measure capacitance by voltage at a constant load. For example https://lygte-info.dk/project/TestControllerDemoBattWithResistor%20UK.html

As for the interface, it will be possible to say only when you try it, but for now it is difficult to imagine in what form it should be.