Switch all classNames helpers to clsx

src/helpers.ts

@@ -30,14 +30,6 @@ export function truncated(input: string, maxLength: number, ellipsis = "...") {
   );
 }
 
-/**
- * A helper method for combining strings of classes in React.
- * @param classes
- */
-export function classNames(...classes: (string | null | undefined)[]) {
-  return classes.filter(Boolean).join(" ");
-}
-
 export function preventDefault(event: SyntheticEvent | Event) {
   event.preventDefault();
 }