[Glitch] Rewrite <LoadingIndicator/> as FC and TS (#25364)

Port a86886b1fd to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/components/scrollable_list.jsx

@@ -17,7 +17,7 @@ import { attachFullscreenListener, detachFullscreenListener, isFullscreen } from
 
 import { LoadMore } from './load_more';
 import { LoadPending } from './load_pending';
-import LoadingIndicator from './loading_indicator';
+import { LoadingIndicator } from './loading_indicator';
 
 const MOUSE_IDLE_DELAY = 300;