Fix 12855 Failed to start game (#12856)

* Fix issue 12826 (UnitSeparator#categorize:213 - java.util.ConcurrentModificationException)

PlacePanel.java
- new method updateUnitsInUnitsToPlacePanel that ensures copying the unit collection (existed already in method updateStep, but not in gameDataChanged or updateUnits)
- Cleanup: extract new methods from declaration of variable placeMapSelectionListener which are getUnitsToPlace, getScrollPaneFromChooser, getPreferredHeight and getPreferredWidth

* PlayerUnitsPanel ToDo done via redraw

Replace
invalidate(); validate(); revalidate();getParent().invalidate();
with SwingComponents.redraw(this);

* tab Players - tooltips for technologies

Smaller fixes:
- SwingConstants instead of JLable
- method setStatColumns with List.toArray
- rename gameData to gameDataSync
- introduce synchronized method TechTableModel.getDataAndInitRowMap()

* Fix 12855 Failed to start game

Example map: World War II v3 1941
UnsupportedOperationException caused by Arrays.asList (=fixed size list) followed with method call add()

game-app/game-core/src/main/java/games/strategy/triplea/ui/StatPanel.java

@@ -22,6 +22,7 @@
 import java.awt.Component;
 import java.awt.GridLayout;
 import java.awt.Image;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
@@ -192,8 +193,11 @@ class StatTableModel extends AbstractTableModel {
     }
 
     void setStatColumns() {
-      final List<IStat> statsList =
-          Arrays.asList(new PuStat(), new ProductionStat(), new UnitsStat(), new TuvStat());
+      final List<IStat> statsList = new ArrayList<>();
+      statsList.add(new PuStat());
+      statsList.add(new ProductionStat());
+      statsList.add(new UnitsStat());
+      statsList.add(new TuvStat());
       if (gameData.getMap().getTerritories().stream().anyMatch(Matches.territoryIsVictoryCity())) {
         statsList.add(new VictoryCityStat());
       }