Add Adafruit IO's Random Data Service

[brentru]

Add access to Adafruit IO's Random Data service for both REST and MQTT clients.

About the Adafruit IO Random Service:

Create random data streams that can generate colors, words, numbers, or pick a value from a custom data set and send it directly to your devices.

The four available data types are:

Pronounceable nonsense words
Colors (RGB values, HSL values, CSS hex, or CSS color name)
Numbers
Preset (sample from a given set of values)
Data randomizes once per minute, so multiple streams using the same seed value will get the same random value, even across user accounts.

You can have up to 20 active randomized word services.