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
part = createPart(descriptor);
		if (part == null) {
			return null;
		}
		return showPart(partState, part, part);
	}
	public MPart showPart(MPart part, PartState partState) {
		Assert.isNotNull(part);
		Assert.isNotNull(partState);
		MPart localPart = findPart(part.getElementId());
		if (localPart != null) {
			return showPart(partState, part, localPart);
		}
		return showPart(partState, part, part);
	}
	public void hidePart(MPart part) {
		if (isInContainer(part)) {
			part.setToBeRendered(false);
			if (part.getTags().contains(REMOVE_ON_HIDE_TAG)) {
				MElementContainer<MUIElement> parent = part.getParent();
				List<MUIElement> children = parent.getChildren();
				children.remove(part);
				
				if (parent.getSelectedElement() == part && !children.isEmpty()) {
					parent.setSelectedElement(children.get(0));
				}
			}
		}
	}
	/*