Replace CP integer ID with a UUID.

This allows unique identification across saves. The front-end needs to
be able to differentiate the first carrier in game A and the first
carrier in game B, but because carriers (and other non-airfield CPs) are
assigned IDs sequentially, collisions were to be expected. The front-end
can't tell the difference between a reloaded game and a new turn, so we
need to ensure different IDs across games.

This is a handy cleanup anyway, since callers constructing CPs no longer
need to manually track the CP ID counter.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/2078.

game/server/controlpoints/models.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from typing import TYPE_CHECKING
+from uuid import UUID
 
 from pydantic import BaseModel
 
@@ -12,7 +13,7 @@ if TYPE_CHECKING:
 
 
 class ControlPointJs(BaseModel):
-    id: int
+    id: UUID
     name: str
     blue: bool
     position: LeafletPoint