Remove LazyLoader class

LazyLoader class is used to lazy load images. It was added a long time ago before the loading="lazy" was introduced and properly supported in browsers. Now it doesn't make sense to have this class so we should remove it completely.

This class also significantly affects performance of the page if it makes lots of DOM operations (streaming for example). Removing this class will meaningfully improve page performance in these cases.

(LazyLoader taking ≈17ms while streaming for each chunk insert)

Blame page streaming comparison with and without LazyLoader

(left is without the class and the right is with the class)