feat(events): remove payload registry, add method to get event classes

We don't need to use the payload schema registry. All our events are dispatched as pydantic models, which are already validated on instantiation.

We do want to add all events to the OpenAPI schema, and we referred to the payload schema registry for this. To get all events, add a simple helper to EventBase. This is functionally identical to using the schema registry.

invokeai/app/api_app.py

@@ -5,7 +5,7 @@ import socket
 from contextlib import asynccontextmanager
 from inspect import signature
 from pathlib import Path
-from typing import Any, cast
+from typing import Any
 
 import torch
 import uvicorn
@@ -17,8 +17,6 @@ from fastapi.openapi.utils import get_openapi
 from fastapi.responses import HTMLResponse
 from fastapi_events.handlers.local import local_handler
 from fastapi_events.middleware import EventHandlerASGIMiddleware
-from fastapi_events.registry.payload_schema import registry as fastapi_events_registry
-from pydantic import BaseModel
 from pydantic.json_schema import models_json_schema
 from torch.backends.mps import is_available as is_mps_available
 
@@ -29,6 +27,7 @@ import invokeai.frontend.web as web_dir
 from invokeai.app.api.no_cache_staticfiles import NoCacheStaticFiles
 from invokeai.app.invocations.model import ModelIdentifierField
 from invokeai.app.services.config.config_default import get_config
+from invokeai.app.services.events.events_common import EventBase
 from invokeai.app.services.session_processor.session_processor_common import ProgressImage
 from invokeai.backend.util.devices import TorchDevice
 
@@ -185,15 +184,13 @@ def custom_openapi() -> dict[str, Any]:
         invoker_schema["class"] = "invocation"
 
     # Add all pydantic event schemas registered with fastapi-events
-    for payload in fastapi_events_registry.data.values():
-        json_schema = cast(BaseModel, payload).model_json_schema(
-            mode="serialization", ref_template="#/components/schemas/{model}"
-        )
+    for event in EventBase.get_events():
+        json_schema = event.model_json_schema(mode="serialization", ref_template="#/components/schemas/{model}")
         if "$defs" in json_schema:
             for schema_key, schema in json_schema["$defs"].items():
                 openapi_schema["components"]["schemas"][schema_key] = schema
             del json_schema["$defs"]
-        openapi_schema["components"]["schemas"][payload.__name__] = json_schema
+        openapi_schema["components"]["schemas"][event.__name__] = json_schema
 
     app.openapi_schema = openapi_schema
     return app.openapi_schema