Dan's massive refactor

Squashing 8 commits by DanAlbert:

- Track theater in ControlPoint.
Simplifies finding the owning theater of a control point. Not used yet.

- Clean some cruft out of FlightPlanBuilder.
- Clean up silly some exception handling.
- Move FlightPlan instantiation into the builder.
I'm working on moving the builder to be owned by the Flight, which will simplify callers that need to create (or recreate) flight plans for a flight.

- Simplify IBuilder constructor.
We have access to the theater via the flight's departure airbase now.

- Move FlightPlan creation into Flight.
For now this is just a callsite cleanup. Later, this will make it easier
to separate unscheduled and scheduled flights into different classes without complicating the layout/scheduling.

- Remove superfluous constructors.
- Remove unused Package field.

qt_ui/windows/SquadronDialog.py

@@ -1,30 +1,25 @@
 import logging
 from typing import Callable, Iterator, Optional
 
-from PySide2.QtCore import (
-    QItemSelectionModel,
-    QModelIndex,
-    Qt,
-    QItemSelection,
-)
+from PySide2.QtCore import QItemSelection, QItemSelectionModel, QModelIndex, Qt
 from PySide2.QtWidgets import (
     QAbstractItemView,
-    QDialog,
-    QListView,
-    QVBoxLayout,
-    QPushButton,
-    QHBoxLayout,
-    QLabel,
     QCheckBox,
     QComboBox,
+    QDialog,
+    QHBoxLayout,
+    QLabel,
+    QListView,
+    QPushButton,
+    QVBoxLayout,
 )
 
-from game.squadrons import Pilot, Squadron
-from game.theater import ControlPoint, ConflictTheater
 from game.ato.flighttype import FlightType
+from game.squadrons import Pilot, Squadron
+from game.theater import ConflictTheater, ControlPoint
 from qt_ui.delegates import TwoColumnRowDelegate
 from qt_ui.errorreporter import report_errors
-from qt_ui.models import SquadronModel, AtoModel
+from qt_ui.models import AtoModel, SquadronModel
 
 
 class PilotDelegate(TwoColumnRowDelegate):
@@ -144,7 +139,6 @@ class SquadronDialog(QDialog):
         super().__init__(parent)
         self.ato_model = ato_model
         self.squadron_model = squadron_model
-        self.theater = theater
 
         self.setMinimumSize(1000, 440)
         self.setWindowTitle(str(squadron_model.squadron))
@@ -200,7 +194,7 @@ class SquadronDialog(QDialog):
             if destination is None:
                 self.squadron.cancel_relocation()
             else:
-                self.squadron.plan_relocation(destination, self.theater)
+                self.squadron.plan_relocation(destination)
             self.ato_model.replace_from_game(player=True)
 
     def check_disabled_button_states(