FIX: Better 0 file size detection and logging (#16116)

When creating files with create-multipart, if the file
size was somehow zero we were showing a very unhelpful
error message to the user. Now we show a nicer message,
and proactively don't call the API if we know the file
size is 0 bytes in JS, along with extra console logging
to help with debugging.

public/javascripts/media-optimization-worker.js

@@ -25,10 +25,10 @@ function resizeWithAspect(
   };
 }
 
-function logIfDebug(message) {
+function logIfDebug(...messages) {
   if (DedicatedWorkerGlobalScope.debugMode) {
     // eslint-disable-next-line no-console
-    console.log(message);
+    console.log(...messages);
   }
 }