Leslies Pool Water Test - Custom Integration

Hey! First time making a custom integration! This is my first pass on pulling the chemical test results from Leslies Pools into HA! This works with the in-store tests as well as the AccuBlue home tests they now offer.

I will be working to refine the setup flow, and also extend for better naming for the device itself and better handling of multiple pools.

This pairs perfectly with the custom pool card front-end too!