Add websocket list APIs for the registries (#16597)

* Add websocket list APIs for the registries

* Remove identifiers

* Fix tests

* Use ordered dict

tests/components/config/test_entity_registry.py

@@ -1,4 +1,6 @@
 """Test entity_registry API."""
+from collections import OrderedDict
+
 import pytest
 
 from homeassistant.helpers.entity_registry import RegistryEntry
@@ -13,6 +15,49 @@ def client(hass, hass_ws_client):
     yield hass.loop.run_until_complete(hass_ws_client(hass))
 
 
+async def test_list_entities(hass, client):
+    """Test list entries."""
+    entities = OrderedDict()
+    entities['test_domain.name'] = RegistryEntry(
+        entity_id='test_domain.name',
+        unique_id='1234',
+        platform='test_platform',
+        name='Hello World'
+    )
+    entities['test_domain.no_name'] = RegistryEntry(
+        entity_id='test_domain.no_name',
+        unique_id='6789',
+        platform='test_platform',
+    )
+
+    mock_registry(hass, entities)
+
+    await client.send_json({
+        'id': 5,
+        'type': 'config/entity_registry/list',
+    })
+    msg = await client.receive_json()
+
+    assert msg['result'] == [
+        {
+            'config_entry_id': None,
+            'device_id': None,
+            'disabled_by': None,
+            'entity_id': 'test_domain.name',
+            'name': 'Hello World',
+            'platform': 'test_platform',
+        },
+        {
+            'config_entry_id': None,
+            'device_id': None,
+            'disabled_by': None,
+            'entity_id': 'test_domain.no_name',
+            'name': None,
+            'platform': 'test_platform',
+        }
+    ]
+
+
 async def test_get_entity(hass, client):
     """Test get entry."""
     mock_registry(hass, {