Add yet-another-react-lightbox package and update .gitignore to exclude node_modules

frontend/node_modules/react-dnd-html5-backend/src/utils/js_utils.ts

@@ -1,30 +0,0 @@
-// cheap lodash replacements
-
-export function memoize<T>(fn: () => T): () => T {
-	let result: T | null = null
-	const memoized = () => {
-		if (result == null) {
-			result = fn()
-		}
-		return result
-	}
-	return memoized
-}
-
-/**
- * drop-in replacement for _.without
- */
-export function without<T>(items: T[], item: T) {
-	return items.filter((i) => i !== item)
-}
-
-export function union<T extends string | number>(itemsA: T[], itemsB: T[]) {
-	const set = new Set<T>()
-	const insertItem = (item: T) => set.add(item)
-	itemsA.forEach(insertItem)
-	itemsB.forEach(insertItem)
-
-	const result: T[] = []
-	set.forEach((key) => result.push(key))
-	return result
-}