Fix: HA reports errors with not correct configuration for DHxx sensor

[tschaban]

Sensor sensor.dht_1_poziom_komfortu has device class None, state class None and unit thus indicating it has a numeric value; however, it has the non-numeric value: OK (<class 'str'>); Please update your configuration if your entity is manually configured, otherwise create a bug report at https://github.com/home-assistant/core/issues?q=is%3Aopen+is%3Aissue+label%3A%22integration%3A+mqtt%22 Sensor sensor.dht_1_percepcja has device class None, state class None and unit thus indicating it has a numeric value; however, it has the non-numeric value: Bardzo komfortowo (<class 'str'>); Please update your configuration if your entity is manually configured, otherwise create a bug report at https://github.com/home-assistant/core/issues?q=is%3Aopen+is%3Aissue+label%3A%22integration%3A+mqtt%22

[tschaban]

changed device class to enum