Add statistics validation (#56020)

* Add statistics validation

* Remove redundant None-check

* Move validate_statistics WS API to recorder

* Apply suggestion from code review

homeassistant/components/recorder/websocket_api.py

@@ -0,0 +1,30 @@
+"""The Energy websocket API."""
+import voluptuous as vol
+
+from homeassistant.components import websocket_api
+from homeassistant.core import HomeAssistant, callback
+
+from .statistics import validate_statistics
+
+
+@callback
+def async_setup(hass: HomeAssistant) -> None:
+    """Set up the recorder websocket API."""
+    websocket_api.async_register_command(hass, ws_validate_statistics)
+
+
+@websocket_api.websocket_command(
+    {
+        vol.Required("type"): "recorder/validate_statistics",
+    }
+)
+@websocket_api.async_response
+async def ws_validate_statistics(
+    hass: HomeAssistant, connection: websocket_api.ActiveConnection, msg: dict
+) -> None:
+    """Fetch a list of available statistic_id."""
+    statistic_ids = await hass.async_add_executor_job(
+        validate_statistics,
+        hass,
+    )
+    connection.send_result(msg["id"], statistic_ids)