Fix logging by deferring campaign data loading.

Logging before we've made it to the logging setup was causing the root
logger to be permanently configured to the default (warning) log
level, so we weren't getting any info or debug logs any more.

Defer the campaign data load until it is needed rather than doing it
at import time. I've also cleaned up a bit so we only load each
campaign once, rather than re-loading the campaign to create the
theater again after the wizard is finished.

theater/conflicttheater.py

@@ -1,5 +1,7 @@
+from __future__ import annotations
+
 import json
-from typing import Dict, Iterator, List, Optional, Tuple
+from typing import Any, Dict, Iterator, List, Optional, Tuple
 
 from dcs.mapping import Point
 from dcs.terrain import (
@@ -163,39 +165,35 @@ class ConflictTheater:
         return cp
 
     @staticmethod
-    def from_file(filename):
-        with open(filename, "r") as content:
-            json_data = json.loads(content.read())
+    def from_json(data: Dict[str, Any]) -> ConflictTheater:
+        theaters = {
+            "Caucasus": CaucasusTheater,
+            "Nevada": NevadaTheater,
+            "Persian Gulf": PersianGulfTheater,
+            "Normandy": NormandyTheater,
+            "The Channel": TheChannelTheater,
+            "Syria": SyriaTheater,
+        }
+        theater = theaters[data["theater"]]
+        t = theater()
+        cps = {}
 
+        for p in data["player_points"]:
+            cp = t.add_json_cp(theater, p)
+            cp.captured = True
+            cps[p["id"]] = cp
+            t.add_controlpoint(cp)
 
-            theaters = {
-                "Caucasus": CaucasusTheater,
-                "Nevada": NevadaTheater,
-                "Persian Gulf": PersianGulfTheater,
-                "Normandy": NormandyTheater,
-                "The Channel": TheChannelTheater,
-                "Syria": SyriaTheater,
-            }
-            theater = theaters[json_data["theater"]]
-            t = theater()
-            cps = {}
+        for p in data["enemy_points"]:
+            cp = t.add_json_cp(theater, p)
+            cps[p["id"]] = cp
+            t.add_controlpoint(cp)
 
-            for p in json_data["player_points"]:
-                cp = t.add_json_cp(theater, p)
-                cp.captured = True
-                cps[p["id"]] = cp
-                t.add_controlpoint(cp)
+        for l in data["links"]:
+            cps[l[0]].connect(cps[l[1]])
+            cps[l[1]].connect(cps[l[0]])
 
-            for p in json_data["enemy_points"]:
-                cp = t.add_json_cp(theater, p)
-                cps[p["id"]] = cp
-                t.add_controlpoint(cp)
-
-            for l in json_data["links"]:
-                cps[l[0]].connect(cps[l[1]])
-                cps[l[1]].connect(cps[l[0]])
-
-            return t
+        return t
 
 
 class CaucasusTheater(ConflictTheater):