Add the beans into a 6-quart slow cooker, add 4 inches of water above the beans, and soak overnight. Drain the beans in the morning and add the 5 cups of fresh water, onion, onion powder, oregano, and chili powder. Cover and cook on LOW for 10 hours. Add the cilantro lime dressing ingredients into a blender; pulse until smooth. Add the salt to taste to the beans and serve over quinoa with the cilantro dressing, shredded cabbage, and cherry tomatoes.