Add support for converting an attached doc and chatting with it

- Document is first converted in the chatinputarea, then sent to the chat component. From there, it's sent in the chat API body and then processed by the backend
- We couldn't directly use a UploadFile type in the backend API because we'd have to convert the api type to a multipart form. This would require other client side migrations without uniform benefit, which is why we do it in this two-phase process. This also gives us capacity to repurpose the moe generic interface down the road.

src/interface/web/app/common/utils.ts

@@ -71,6 +71,16 @@ export function useIsMobileWidth() {
     return isMobileWidth;
 }
 
+export const convertBytesToText = (fileSize: number) => {
+    if (fileSize < 1024) {
+        return `${fileSize} B`;
+    } else if (fileSize < 1024 * 1024) {
+        return `${(fileSize / 1024).toFixed(2)} KB`;
+    } else {
+        return `${(fileSize / (1024 * 1024)).toFixed(2)} MB`;
+    }
+};
+
 export function useDebounce<T>(value: T, delay: number): T {
     const [debouncedValue, setDebouncedValue] = useState<T>(value);