code review refactor

[ZavenArra]

• wip: sigfigs managements for calibration
• wip: create math function to save space
• wip: sig figs
• feat: sig figs for generic analog calib
• fix: cleanup
• wip: store variance and burst for cal
• implemented driver template and adafruit dht22 driver
• fix columns, spare comma before battery voltage, not sure where though
• fix: buffer size and milliseconds for human timestamp, json name of dht22
• fix: update help command list, add gpio-test to toggle pc12 for testing components
• get-config notify to debug messages
• fix: character limit on deployment-id
• fix timestamps due to sleep function
• fix: restructuring order of structs by size, untested
• fix: improve get-rtc message
• fix: cleanup
• chore: add some useless text
• feat: refactoring and code review, move some functionality to sensor base class and cleanup