Refactor shared mqtt schema's to new module (#117944)

* Refactor mqtt schema's to new module

* Remove unrelated change

homeassistant/components/mqtt/sensor.py

@@ -42,7 +42,6 @@ from .config import MQTT_RO_SCHEMA
 from .const import CONF_ENCODING, CONF_QOS, CONF_STATE_TOPIC, PAYLOAD_NONE
 from .debug_info import log_messages
 from .mixins import (
-    MQTT_ENTITY_COMMON_SCHEMA,
     MqttAvailability,
     MqttEntity,
     async_setup_entity_entry_helper,
@@ -54,6 +53,7 @@ from .models import (
     ReceiveMessage,
     ReceivePayloadType,
 )
+from .schemas import MQTT_ENTITY_COMMON_SCHEMA
 
 _LOGGER = logging.getLogger(__name__)