Add getter for the supplied error status of ErrorEditorPart

Currently the ErrorEditorPart supplied status can only be seen by a user
in the UI, this is a bit unfortunate if for example in an automated test
and ErrorEditorPart is seen there is no way to find out what's going
wrong and give good assertion messages.

This adds ErrorEditorPart#getError to allow such programmatic
investigations if ErrorEditorPart is seen in the code.

Author: laeubi

bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/ErrorEditorPart.java

@@ -94,4 +94,12 @@ public void dispose() {
 		super.dispose();
 		parentControl = null;
 	}
+
+	/**
+	 * @return Returns the error status or <code>null</code> if part was created
+	 *         without an explicit error status.
+	 */
+	public IStatus getError() {
+		return error;
+	}
 }