added support for home assistant postgres database and convenience function to get state of entity

utils/database/dataframes/__init__.py

@@ -0,0 +1,7 @@
+"""Definition of dataframes."""
+
+from .sensor_state import SensorStateSchema
+
+__all__ = [
+    "SensorStateSchema",
+]

utils/database/dataframes/sensor_state.py

@@ -0,0 +1,12 @@
+"""Definition of SensorStateSchema dataframe schema."""
+
+from typing import Optional
+import pandera.pandas as pa
+import pandas as pd
+
+
+class SensorStateSchema(pa.DataFrameModel):
+    """Schema for sensor state dataframe."""
+
+    time: pd.DatetimeTZDtype = pa.Field(dtype_kwargs={"tz": "UTC"})
+    state: Optional[str]