Add data entry flow helper (#13935)

* Extract data entry flows HTTP views into helper

* Remove use of domain

* Lint

* Fix tests

* Update doc

homeassistant/config_entries.py

@@ -338,7 +338,7 @@ class ConfigEntries:
         if component not in self.hass.config.components:
             return True
 
-        await entry.async_unload(
+        return await entry.async_unload(
             self.hass, component=getattr(self.hass.components, component))
 
     async def _async_save_entry(self, result):
@@ -362,6 +362,8 @@ class ConfigEntries:
             await async_setup_component(
                 self.hass, entry.domain, self._hass_config)
 
+        return entry
+
     async def _async_create_flow(self, handler):
         """Create a flow for specified handler.