Fix the tooltips for the two drawer buttons at the top

One of them didn't even have a tooltip, which is a simple oversight
since it already has accessible text. The tooltips now use the attached
property instead of creating a new QQC2.ToolTip too.

(cherry picked from commit 7daae6a2d9)

src/qml/ExploreComponent.qml

@@ -107,6 +107,10 @@ RowLayout {
             sequence: "Ctrl+F"
             onActivated: searchButton.clicked()
         }
+
+        QQC2.ToolTip.visible: hovered
+        QQC2.ToolTip.text: text
+        QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
     }
 
     QQC2.ToolButton {
@@ -129,9 +133,9 @@ RowLayout {
             }
         }
 
-        QQC2.ToolTip {
+        QQC2.ToolTip.visible: hovered
-            text: parent.text
+        QQC2.ToolTip.text: text
-        }
+        QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
     }
 
     Component {