Api improvements (#15327)

* Organize api files

* Add more API definitions for events

* Add export select by ID

* Typing fixes

* Update openapi spec

* Change type

* Fix test

* Fix message

* Fix tests

frigate/api/defs/request/app_body.py

@@ -0,0 +1,19 @@
+from pydantic import BaseModel
+
+
+class AppConfigSetBody(BaseModel):
+    requires_restart: int = 1
+
+
+class AppPutPasswordBody(BaseModel):
+    password: str
+
+
+class AppPostUsersBody(BaseModel):
+    username: str
+    password: str
+
+
+class AppPostLoginBody(BaseModel):
+    user: str
+    password: str