Ensure PackedFile is always closed and remove PackedFile.finalize()

Almost all `PackedFile` instances are wrapped in a try-with-resources to ensure they are always closed. The one
exception guarantees the instance is closed in a `finally` block.

The following places used to (at least partially) rely on PackedFile.finalize() but now use try-with-resources:
- `ImageFileImagePanelModel.getDecorations()`
- `PersistenceUtils.loadCampaignProperties()`
- `PackedFile`

The following place used to call `PackedFile.close()` in a `finally` block now uses try-with-resources:
- `PersistenceUtil.loadCampaign()`

The following place still uses a `finally` block because there is extra logic surrounding the close() call:
- `PersistenceUtil.saveCampaign()`

src/main/java/net/rptools/lib/io/PackedFile.java

@@ -753,11 +753,6 @@ public void close() {
     dirty = !file.exists();
   }
 
-  @Override
-  protected void finalize() throws Throwable {
-    close();
-  }
-
   protected File getExplodedFile(String path) {
     return new File(tmpFile, path);
   }

src/main/java/net/rptools/maptool/client/ui/assetpanel/ImageFileImagePanelModel.java

@@ -133,8 +133,7 @@ public Image[] getDecorations(int index) {
     if (!Token.isTokenFile(fileList.get(index).getName())) {
       return null;
     }
-    try {
-      PackedFile pakFile = new PackedFile(fileList.get(index));
+    try (PackedFile pakFile = new PackedFile(fileList.get(index))) {
       Object isHeroLab = pakFile.getProperty(PersistenceUtil.HERO_LAB);
       if (isHeroLab != null && (boolean) isHeroLab) {
         return new Image[] {herolabDecorationImage};

src/main/java/net/rptools/maptool/util/PersistenceUtil.java

@@ -435,9 +435,7 @@ public static PersistedCampaign loadCampaign(File campaignFile) throws IOExcepti
     PersistedCampaign persistedCampaign = null;
 
     // Try the new way first
-    PackedFile pakFile = null;
-    try {
-      pakFile = new PackedFile(campaignFile);
+    try (PackedFile pakFile = new PackedFile(campaignFile)) {
       pakFile.setModelVersionManager(campaignVersionManager);
 
       // Sanity check
@@ -453,7 +451,14 @@ public static PersistedCampaign loadCampaign(File campaignFile) throws IOExcepti
       } catch (ConversionException ce) {
         // Ignore the exception and check for "campaign == null" below...
         MapTool.showError("PersistenceUtil.error.campaignVersion", ce);
+      } catch (ClassCastException cce) {
+        // Ignore the exception and check for "campaign == null" below...
+        MapTool.showWarning(
+            I18N.getText(
+                "PersistenceUtil.warn.campaignWrongFileType",
+                pakFile.getContent().getClass().getSimpleName()));
       }
+
       if (persistedCampaign != null) {
         // Now load up any images that we need
         // Note that the values are all placeholders
@@ -480,19 +485,12 @@ public static PersistedCampaign loadCampaign(File campaignFile) throws IOExcepti
     } catch (OutOfMemoryError oom) {
       MapTool.showError("Out of memory while reading campaign.", oom);
       return null;
-    } catch (ClassCastException cce) {
-      MapTool.showWarning(
-          I18N.getText(
-              "PersistenceUtil.warn.campaignWrongFileType",
-              pakFile.getContent().getClass().getSimpleName()));
     } catch (RuntimeException rte) {
       MapTool.showError("PersistenceUtil.error.campaignRead", rte);
     } catch (Error e) {
       // Probably an issue with XStream not being able to instantiate a given class
       // The old legacy technique probably won't work, but we should at least try...
       MapTool.showError("PersistenceUtil.error.unknown", e);
-    } finally {
-      if (pakFile != null) pakFile.close();
     }
 
     // No longer try to load a legacy (very early 1.3 and before) campaign
@@ -511,7 +509,7 @@ private static String getThumbFilename(PackedFile pakFile) throws IOException {
 
   public static BufferedImage getTokenThumbnail(File file) throws Exception {
     BufferedImage thumb;
-    try (PackedFile pakFile = new PackedFile(file); ) {
+    try (PackedFile pakFile = new PackedFile(file)) {
       // Jamz: Lets use the Large thumbnail if needed
       String thumbFileName = getThumbFilename(pakFile);
 
@@ -857,9 +855,7 @@ private static boolean versionCheck(String progVersion) {
   }
 
   public static CampaignProperties loadCampaignProperties(File file) {
-    PackedFile pakFile = null;
-    try {
-      pakFile = new PackedFile(file);
+    try (PackedFile pakFile = new PackedFile(file)) {
       String progVersion = (String) pakFile.getProperty(PROP_VERSION);
       if (!versionCheck(progVersion)) return null;
       CampaignProperties props = null;
@@ -879,10 +875,8 @@ public static CampaignProperties loadCampaignProperties(File file) {
       return props;
     } catch (IOException e) {
       try {
-        if (pakFile != null)
-          pakFile.close(); // first close PackedFile (if it was opened) 'cuz some stupid OSes won't
-        // allow a file to be opened twice (ugh).
-        pakFile = null;
+        // Some OSes won't allow a file to be opened twice (ugh). But we're okay here since
+        // try-with-resources ensures that .close() was already called by this point.
         return loadLegacyCampaignProperties(file);
       } catch (IOException ioe) {
         MapTool.showError("PersistenceUtil.error.campaignPropertiesLegacy", ioe);

src/test/java/net/rptools/maptool/client/swing/preference/net/rptools/lib/io/PackedFileTest.java

@@ -33,9 +33,10 @@ public class PackedFileTest {
   @Test
   public void emptySave(@TempDir File tempDir) throws IOException {
     File f = new File(tempDir, PACKED_TEST_FILE);
-    PackedFile pf = new PackedFile(f);
-    pf.save();
-    assertTrue(f.exists());
+    try (PackedFile pf = new PackedFile(f)) {
+      pf.save();
+      assertTrue(f.exists());
+    }
   }
 
   @Test