* Created a binary sensor and corrected some review comments.
* Updated the poolsense class and its interface to handle credentials better
* Moved the client session to the PoolSense class.
* Apply suggestions from code review
* Update binary_sensor.py
* Update homeassistant/components/poolsense/__init__.py
* Update sensor.py
* Update binary_sensor.py
Co-authored-by: Chris Talkington <chris@talkingtontech.com>