Add mqtt encoding support for publishing (#62739)

* encoding support for mqtt publishing - todo tests

* signature allows None values for qos and retain

* common test for mqtt publishing encoding

* better test with command templates

* more tests

* fix tests alarm control panel+tests light basic

* tests light json and template

* add tests vacuum and fix tests light_template

tests/components/mqtt/test_switch.py

@@ -32,6 +32,7 @@ from .test_common import (
     help_test_entity_device_info_with_identifier,
     help_test_entity_id_update_discovery_update,
     help_test_entity_id_update_subscriptions,
+    help_test_publishing_with_custom_encoding,
     help_test_setting_attribute_via_mqtt_json_message,
     help_test_setting_attribute_with_template,
     help_test_setting_blocked_attribute_via_mqtt_json_message,
@@ -467,3 +468,50 @@ async def test_entity_debug_info_message(hass, mqtt_mock):
     await help_test_entity_debug_info_message(
         hass, mqtt_mock, switch.DOMAIN, DEFAULT_CONFIG
     )
+
+
+@pytest.mark.parametrize(
+    "service,topic,parameters,payload,template",
+    [
+        (
+            switch.SERVICE_TURN_ON,
+            "command_topic",
+            None,
+            "ON",
+            None,
+        ),
+        (
+            switch.SERVICE_TURN_OFF,
+            "command_topic",
+            None,
+            "OFF",
+            None,
+        ),
+    ],
+)
+async def test_publishing_with_custom_encoding(
+    hass,
+    mqtt_mock,
+    caplog,
+    service,
+    topic,
+    parameters,
+    payload,
+    template,
+):
+    """Test publishing MQTT payload with different encoding."""
+    domain = switch.DOMAIN
+    config = DEFAULT_CONFIG[domain]
+
+    await help_test_publishing_with_custom_encoding(
+        hass,
+        mqtt_mock,
+        caplog,
+        domain,
+        config,
+        service,
+        topic,
+        parameters,
+        payload,
+        template,
+    )