use logo for fiat currencies

desktop/src/main/java/haveno/desktop/images.css

@@ -313,6 +313,10 @@
     -fx-image: url("../../images/settings.png");
 }
 
+#image-fiat-logo {
+    -fx-image: url("../../images/fiat_logo_light_mode.png");
+}
+
 #image-btc-logo {
     -fx-image: url("../../images/btc_logo.png");
 }

desktop/src/main/java/haveno/desktop/theme-dark.css

@@ -643,3 +643,7 @@
 .regular-text-color {
     -fx-text-fill: -bs-text-color;
 }
+
+#image-fiat-logo {
+    -fx-image: url("../../images/fiat_logo_dark_mode.png");
+}

desktop/src/main/java/haveno/desktop/util/GUIUtil.java

@@ -349,11 +349,11 @@ protected void updateItem(CurrencyListItem item, boolean empty) {
                             break;
                         default:
 
-                            // use icons for crypto
-                            if (CurrencyUtil.isCryptoCurrency(code)) {
+                            // use icon if available
+                            StackPane currencyIcon = getCurrencyIcon(code);
+                            if (currencyIcon != null) {
                                 label1.setText("");
-                                StackPane iconWrapper = new StackPane(getCurrencyIcon(code)); // TODO: icon must be wrapped in StackPane for reliable rendering on linux
-                                label1.setGraphic(iconWrapper);
+                                label1.setGraphic(currencyIcon);
                             }
 
                             if (preferences.isSortMarketCurrenciesNumerically() && item.numTrades > 0) {
@@ -459,10 +459,11 @@ protected void updateItem(TradeCurrency item, boolean empty) {
                             break;
                         default:
 
-                            // use icons for crypto
-                            if (CurrencyUtil.isCryptoCurrency(item.getCode())) {
+                            // use icon if available
+                            StackPane currencyIcon = getCurrencyIcon(code);
+                            if (currencyIcon != null) {
                                 label1.setText("");
-                                label1.setGraphic(getCurrencyIcon(item.getCode()));
+                                label1.setGraphic(currencyIcon);
                             }
 
                             boolean isCrypto = CurrencyUtil.isCryptoCurrency(code);
@@ -502,10 +503,11 @@ protected void updateItem(TradeCurrency item, boolean empty) {
                     Label label2 = new AutoTooltipLabel(item.getNameAndCode());
                     label2.getStyleClass().add("currency-label");
 
-                    // use icons for crypto
-                    if (CurrencyUtil.isCryptoCurrency(item.getCode())) {
+                    // use icon if available
+                    StackPane currencyIcon = getCurrencyIcon(item.getCode());
+                    if (currencyIcon != null) {
                         label1.setText("");
-                        label1.setGraphic(getCurrencyIcon(item.getCode()));
+                        label1.setGraphic(currencyIcon);
                     }
 
                     box.getChildren().addAll(label1, label2);
@@ -1278,19 +1280,31 @@ private static <T> void updateEdgeColumnStyleClasses(TableView<T> tableView) {
         return contentColumns;
     }
 
-    public static ImageView getCurrencyIcon(String currencyCode) {
-        return getCurrencyIcon(currencyCode, 24);
+    private static ImageView getCurrencyImageView(String currencyCode) {
+        return getCurrencyImageView(currencyCode, 24);
     }
 
-    public static ImageView getCurrencyIcon(String currencyCode, double size) {
+    private static ImageView getCurrencyImageView(String currencyCode, double size) {
         if (currencyCode == null) return null;
-        ImageView iconView = new ImageView();
-        iconView.setFitWidth(size);
-        iconView.setPreserveRatio(true);
-        iconView.setSmooth(true);
-        iconView.setCache(true);
-        iconView.setId(getImageId(currencyCode));
-        return iconView;
+        String imageId = getImageId(currencyCode);
+        if (imageId == null) return null;
+        ImageView icon = new ImageView();
+        icon.setFitWidth(size);
+        icon.setPreserveRatio(true);
+        icon.setSmooth(true);
+        icon.setCache(true);
+        icon.setId(imageId);
+        return icon;
+    }
+
+    public static StackPane getCurrencyIcon(String currencyCode) {
+        ImageView icon = getCurrencyImageView(currencyCode);
+        return icon == null ? null : new StackPane(icon);
+    }
+
+    public static StackPane getCurrencyIcon(String currencyCode, double size) {
+        ImageView icon = getCurrencyImageView(currencyCode, size);
+        return icon == null ? null : new StackPane(icon);
     }
 
     public static StackPane getCurrencyIconWithBorder(String currencyCode) {
@@ -1300,12 +1314,9 @@ public static StackPane getCurrencyIconWithBorder(String currencyCode) {
     public static StackPane getCurrencyIconWithBorder(String currencyCode, double size, double borderWidth) {
         if (currencyCode == null) return null;
 
-        ImageView icon = getCurrencyIcon(currencyCode, size);
+        ImageView icon = getCurrencyImageView(currencyCode, size);
         icon.setFitWidth(size - 2 * borderWidth);
         icon.setFitHeight(size - 2 * borderWidth);
-        icon.setPreserveRatio(true);
-        icon.setSmooth(true);
-        icon.setCache(true);
 
         StackPane circleWrapper = new StackPane(icon);
         circleWrapper.setPrefSize(size, size);
@@ -1327,7 +1338,9 @@ public static StackPane getCurrencyIconWithBorder(String currencyCode, double si
 
     private static String getImageId(String currencyCode) {
         if (currencyCode == null) return null;
-        return "image-" + currencyCode.toLowerCase() + "-logo";
+        if (CurrencyUtil.isCryptoCurrency(currencyCode)) return "image-" + currencyCode.toLowerCase() + "-logo";
+        if (CurrencyUtil.isFiatCurrency(currencyCode)) return "image-fiat-logo";
+        return null;
     }
 
     public static void adjustHeightAutomatically(TextArea textArea) {