feat: extend Apprise JSON notification functionality with programmatic data (#1355)

* Fixed incorrect generic deleted notification text

* Added custom "event_source" header for json notifs

* Added internal reference data to event notifs

* Added event listeners to shopping list items

* Fixed type issues

* moved JSON event source k:v pairs to message body

* added hook for all supported custom endpoints
fixed bug that excluded non-custom notification types

* created event_source class to replace loosely-typed dict

* fixed silent error when dispatching a null task

* moved url updates to static function

* added unit tests for event_source url manipulation

* removed array from event bus (it's unsupported)

tests/utils/factories.py

@@ -16,6 +16,10 @@ def random_bool() -> bool:
     return bool(random.getrandbits(1))
 
 
+def random_int(min=-4294967296, max=4294967296) -> int:
+    return random.randint(min, max)
+
+
 def user_registration_factory(advanced=None, private=None) -> CreateUserRegistration:
     return CreateUserRegistration(
         group=random_string(),