Bug 313407 EPartService needs to use EModelService's bringToTop method
The EMS variant considers shared parts, the EPS should delegate accordingly.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/PartServiceImpl.java
Object child = parentContext.get(IContextConstants.ACTIVE_CHILD);
		if (child == oldContext) {
			parentContext.set(IContextConstants.ACTIVE_CHILD,
					part == null ? null : part.getContext());
		}
	}
	public MPart findPart(String id) {
		MApplicationElement element = modelService.find(id, rootContainer);
		if (element instanceof MPlaceholder) {
			element = ((MPlaceholder) element).getRef();
		}
		return element instanceof MPart ? (MPart) element : null;
	}
	public Collection<MPart> getParts() {
		return modelService.findElements(rootContainer, null, MPart.class, null);
	}
	public boolean isPartVisible(MPart part) {
		if (isInContainer(part)) {
			MElementContainer<?> parent = part.getParent();
			if (parent instanceof MPartStack) {
				return parent.getSelectedElement() == part;
			}
			return part.isVisible();
		}
		return false;
	}
	private boolean isInContainer(MPart part) {
		MUIElement p = modelService.find(part.getElementId(), rootContainer);
		if (p != null)
			return true;