Create update_model endpoint

TSIA, backend implementation of `update_model()`. The other changes were from running the auto-formatter:
```
fd --glob '*.py'  python/src/aiconfig/editor/server | xargs python -m 'scripts.lint' --mode=fix --files
```

## Test Plan
Follow dev README to setup the local editor: https://github.com/lastmile-ai/aiconfig/tree/main/python/src/aiconfig/editor#dev, then run this command
```
curl http://localhost:8080/api/update_model -d curl http://localhost:8080/api/update_model -d '{"prompt_name":"get_activities", "model_name": "gpt-4", "settings": {"top_p": 0.9}}' -X POST -H 'Content-Type: application/json'
```
Notice that the model name is updated to `gpt-4`, and the `top_p` is now at 0.9

https://github.com/lastmile-ai/aiconfig/assets/151060367/3031fa59-8925-495c-a5eb-e56ec65b7fba

python/src/aiconfig/editor/server/server.py

@@ -1,5 +1,5 @@
 import logging
-from typing import Any, Type
+from typing import Any, Dict, Type
 
 import lastmile_utils.lib.core.api as core_utils
 import result
@@ -226,3 +226,18 @@ def delete_prompt() -> FlaskResponse:
 
     operation = make_op_run_method(method_name)
     return run_aiconfig_operation_with_request_json(aiconfig, request_json, f"method_{method_name}", operation, signature)
+
+
+@app.route("/api/update_model", methods=["POST"])
+def update_model() -> FlaskResponse:
+    state = get_server_state(app)
+    aiconfig = state.aiconfig
+    request_json = request.get_json()
+
+    model_name: str | None = request_json.get("model_name")
+    settings: Dict[str, Any] | None = request_json.get("settings")
+    prompt_name: str | None = request_json.get("prompt_name")
+
+    operation = make_op_run_method(MethodName("update_model"))
+    operation_args: Result[OpArgs, str] = result.Ok(OpArgs({"model_name": model_name, "settings": settings, "prompt_name": prompt_name}))
+    return run_aiconfig_operation_with_op_args(aiconfig, "update_model", operation, operation_args)

python/src/aiconfig/editor/server/server_utils.py

@@ -8,16 +8,17 @@
 from enum import Enum
 from types import ModuleType
 from typing import Any, Callable, NewType, Optional, Type, TypeVar, cast
-from aiconfig.registry import ModelParserRegistry
-from aiconfig.schema import Prompt, PromptMetadata
 
 import lastmile_utils.lib.core.api as core_utils
 import result
 from aiconfig.Config import AIConfigRuntime
+from aiconfig.registry import ModelParserRegistry
 from flask import Flask
 from pydantic import field_validator
 from result import Err, Ok, Result
 
+from aiconfig.schema import Prompt, PromptMetadata
+
 MethodName = NewType("MethodName", str)
 
 logging.getLogger("werkzeug").disabled = True