uncooked lasagna noodles • onion, chopped • garlic, chopped • (14.5 ounce) can vegetable broth • chopped fresh rosemary • (14 ounce) can marinated artichoke hearts, drained and chopped • (10 ounce) package frozen chopped spinach, thawed, drained and squeezed dry • (28 ounce) jar tomato pasta sauce • shredded mozzarella cheese, divided • (4 ounce) package herb and garlic feta, crumbled