Fix wrong styling of link icon in dark mode

It also removes a style workaround that is not needed anymore.
Side note: the style that was set never existed anyways.

desktop/src/main/java/bisq/desktop/bisq.css

@@ -838,6 +838,7 @@ textfield */
     -fx-border-width: 0px;
     -fx-underline: true;
     -fx-text-fill: -bs-rd-font-dark;
+    -fx-fill: -bs-rd-font-dark;
 }
 
 .hyperlink.no-underline {
@@ -846,6 +847,7 @@ textfield */
 
 .hyperlink:hover {
     -fx-text-fill: -bs-text-color;
+    -fx-fill: -bs-text-color;
 }
 
 .hyperlink:hover,

desktop/src/main/java/bisq/desktop/components/HyperlinkWithIcon.java

@@ -81,9 +81,6 @@ public class HyperlinkWithIcon extends Hyperlink {
 
         setContentDisplay(ContentDisplay.RIGHT);
         setGraphicTextGap(7.0);
-
-        //TODO: replace workaround of setting the style this way
-        tooltipProperty().addListener((observable, oldValue, newValue) -> newValue.getStyleClass().add("tooltip-hyperlink-icon"));
     }
 
     public void clear() {