Bug 59045 no more support to reuse editors
The old search provided the option Window>Preferences>Workbench>Search>"Reuse Editors to Show Matches". This option is no longer honored by the new search implementation. This is a loss of function and we have to revive this option.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/JavaSearchResultPage.java
* Precondition here: the viewer must be showing a tree with a LevelContentProvider.
	 * @param order
	 */
	void setGrouping(int grouping) {
		fCurrentGrouping= grouping;
		StructuredViewer viewer= getViewer();
		LevelTreeContentProvider cp= (LevelTreeContentProvider) viewer.getContentProvider();
		cp.setLevel(grouping);
		updateGroupingActions();
		getSettings().put(KEY_GROUPING, fCurrentGrouping);
	}
	
	protected StructuredViewer getViewer() {
		
		return super.getViewer();
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.search.ui.text.AbstractTextSearchViewPage#restoreState(org.eclipse.ui.IMemento)
	 */
	public void restoreState(IMemento memento) {
		super.restoreState(memento);
		try {
			fCurrentSortOrder= getSettings().getInt(KEY_SORTING);
		} catch (NumberFormatException e) {
			fCurrentSortOrder=  SortingLabelProvider.SHOW_ELEMENT_CONTAINER;
		}
		try {
			fCurrentGrouping= getSettings().getInt(KEY_GROUPING);
		} catch (NumberFormatException e) {