Battery level with proportional filter and lookup table (#3216)

* Add battery level with lookup table

now uses a lookup table to better calculate battery level of different cells

* LifePo4 and PB battery table - added voltage filter

removed delay from adc reading, added a software filter to smooth out voltage readings. In those applications battery would last hours to days, no sudden change should be expected so a less frequent voltage reading or a more aggressive filtering could be done.
Note: to speed up convergence i initiliazied the last value to the minimum voltage, there are other and better ways to init the filter.

Added LiFePO4 and PB  open circuit volta battery tables,

* Fixed ADC_CTRL , Checks for valid ADC readings

line 230/386 For heltec v3 and heltec tracker a different approach was used with the ADC_CTRL pin, now is more uniform using the same code for the 3 boards.

line 236 Check if the raw reading we are getting is Valid or not, count only the valid readings. This could lead to a division by 0 (improbable) so that's why at line 258 there is a check for that.

* updated OCV values

updated value to not OCV but to very low current, almost the same anyway

* Added Alkaline/Nimh voltage curve

Added Alkaline/Nimh voltage curve for AA/AAA and similar cells

* updates variants for new capacity measurement

* trunk reformatting

* trunk fmt

* Add LTO chemistry

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
Co-authored-by: code8buster <20384924+code8buster@users.noreply.github.com>

variants/heltec_v2.1/variant.h

@@ -29,7 +29,8 @@
 #define LORA_DIO1 35 // https://www.thethingsnetwork.org/forum/t/big-esp32-sx127x-topic-part-3/18436
 #define LORA_DIO2 34 // Not really used
 
-#define ADC_MULTIPLIER 3.8
+#define ADC_MULTIPLIER 3.2 // 220k + 100k (320k/100k=3.2)
+// #define ADC_WIDTH ADC_WIDTH_BIT_10
 
 #define BATTERY_PIN 37 // A battery voltage measurement pin, voltage divider connected here to measure battery voltage
 #define ADC_CHANNEL ADC1_GPIO37_CHANNEL