Add support for subentries to config entries (#117355)

* Add support for subentries to config entries

* Improve error handling and test coverage

* Include subentry_id in subentry containers

* Auto-generate subentry_id and add optional unique_id

* Tweak

* Update tests

* Fix stale docstring

* Address review comments

* Typing tweaks

* Add methods to ConfigEntries to add and remove subentry

* Improve ConfigSubentryData typed dict

* Update test snapshots

* Adjust tests

* Fix unique_id logic

* Allow multiple subentries with None unique_id

* Add number of subentries to config entry JSON representation

* Add subentry translation support

* Allow integrations to implement multiple subentry flows

* Update translations schema

* Adjust exception text

* Change subentry flow init step to user

* Prevent creating a subentry with colliding unique_id

* Update tests

* Address review comments

* Remove duplicaetd unique_id collision check

* Remove change from the future

* Improve test coverage

* Add default value for unique_id

tests/common.py

@@ -1000,6 +1000,7 @@ class MockConfigEntry(config_entries.ConfigEntry):
         reason=None,
         source=config_entries.SOURCE_USER,
         state=None,
+        subentries_data=None,
         title="Mock Title",
         unique_id=None,
         version=1,
@@ -1016,6 +1017,7 @@ class MockConfigEntry(config_entries.ConfigEntry):
             "options": options or {},
             "pref_disable_new_entities": pref_disable_new_entities,
             "pref_disable_polling": pref_disable_polling,
+            "subentries_data": subentries_data or (),
             "title": title,
             "unique_id": unique_id,
             "version": version,