Add Turner Turbidity Plus sensor

[mbarneytu]

Adding the Turner Turbidity Plus sensor, with wiper: https://www.turnerdesigns.com/turbidity-plus-submersible-sensor

I based this upon the TurnerCyclops class and added a few changes:

• Used differential signaling to help protect against signal noise over long sensor cables (ref: https://learn.adafruit.com/adafruit-4-channel-adc-breakouts/signal-connections).
• I used an external ADS1115 ADC to capture the sensor's full 0-5V range, and controlled it using I2C via a logic-level converter (Adafruit BSS138) since the Mayfly operates at 3.3V.
• Retained the ability to use a voltage divider instead of a logic-level converter.
• Enabled the ADS1115's programmable gain amplifier.
• Added wiper functionality: the wiper runs one cycle before each measurement, using the pin specified by wiperTriggerPin.
• Modified the maximum adcVoltage threshold to 5.3V (the ADS1115's max, when its VDD is 5V).

[aufdenkampe]

@SRGDamia1, this is old, but it could be nice to merge this to better support Trout Unlimited use cases.

[aufdenkampe]

@SRGDamia1, should we add this to Milestone for release v0.36?