Add - Sleep Modes

[brentru]

This pull request adds support for ESP32x sleep functionality to the WipperSnapper API, enabling the option of having low-power WipperSnapper nodes.

Sleep "Mode" Overview

• message Enter contains configuration for a node to configure itself for entering a sleep mode.

  • mode - Required sleep mode, supports the primary ESP32x sleep modes - Light Sleep and Deep Sleep
    • Note: While this may eventually be automatically selected and filled by the broker depending on the WakeupSource and TimerConfig's duration. However, I think we'll always want to expose this field (even if we hide it or put it under an "advanced options" dropdown).
  • WakeupSource - There are several wakeup sources in the sleep modes. However, we are only supporting timer-based wake (RTC/timer) and pin-based wake (external GPIO)
  • config contains mode configuration

• message Goodnight contains a message to indicate the device is going to sleep. It is published to Adafruit IO. It may eventually be required to expanded to contain a failure state (if the device fails to go into deep sleep).

• message Wake - Sent when a device wakes up from sleep.

  • Contains a wake reason (EspWakeCause)
    • We are expecting to expand this to multiple chipsets if they have compatibility, so WakeCause is a oneof.
  • Contains a calculated sleep duration (may be used to determine drift, or debug if the device actually went to sleep)

[tyeth]

wonder if we have 3=w_pins, 4=timer+pin, 5=timer+pins. Maybe pin could just use the pins mask version instead so we only need an extra one for 3=timer+pin

[brentru]

This is a MVP. We can always extend this enum in the future to support EXT1 (multiple pin) wakeup source.