Add hints for history navigation to FindReplaceOverlay

In the FindReplaceOverlay, the search and replace histories can be
navigated via pressing arrow up and down keys. This adds an according
hint to the hint messages of the input fields.

Author: HeikoKlare

bundles/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/internal/findandreplace/FindReplaceMessages.properties

@@ -56,8 +56,8 @@ FindReplaceOverlay_caseSensitiveButton_toolTip=Match case
 FindReplaceOverlay_wholeWordsButton_toolTip=Match whole word
 FindReplaceOverlay_replaceButton_toolTip=Replace
 FindReplaceOverlay_replaceAllButton_toolTip=Replace all
-FindReplaceOverlay_searchBar_message=Find
-FindReplaceOverlay_replaceBar_message=Replace
+FindReplaceOverlay_searchBar_message=Find (\u2195 for history)
+FindReplaceOverlay_replaceBar_message=Replace (\u2195 for history)
 FindReplaceOverlay_replaceToggle_toolTip=Toggle input for replace
 FindReplaceOverlay_searchHistory_toolTip=Show search history
 FindReplaceOverlay_replaceHistory_toolTip=Show replace history