Add support for time entities (#6399)

* Add time entities

* Add tests

* Add myself to datetime codeowners

* Fix publishing times with 0 values

* Log performing TimeCall

* Implement `on_time` trigger

* Rename var

* Fix initial value for time

* Add arg name for clarity

* Remove useless checks

esphome/core/component_iterator.h

@@ -60,6 +60,9 @@ class ComponentIterator {
 #ifdef USE_DATETIME_DATE
   virtual bool on_date(datetime::DateEntity *date) = 0;
 #endif
+#ifdef USE_DATETIME_TIME
+  virtual bool on_time(datetime::TimeEntity *time) = 0;
+#endif
 #ifdef USE_TEXT
   virtual bool on_text(text::Text *text) = 0;
 #endif
@@ -120,6 +123,9 @@ class ComponentIterator {
 #ifdef USE_DATETIME_DATE
     DATETIME_DATE,
 #endif
+#ifdef USE_DATETIME_TIME
+    DATETIME_TIME,
+#endif
 #ifdef USE_TEXT
     TEXT,
 #endif