Calculate md5 hashes of uploaded files

Discord does some weird stuff to file data, and we have to reverse it.

src/utils/index.ts

@@ -5,6 +5,7 @@ export * from './ban-utils';
 export * from './channel-utils';
 export * from './commands';
 export * from './e621-utils';
+export * from './file-utils';
 export * from './interaction-utils';
 export * from './message-logger';
 export * from './message-utils';