[Fix] Removes ability from non-cargonia plebians to confirm cargo ord…

…ers from request console (tgstation#83627)

## About The Pull Request
Turns out, `requestonly` var never passed to frontend and were always
false in tgui because of that. I've changed it to `can_send` since this
button is responsible for sending and not requesting

<details>
<summary>before</summary>
  

![image](https://github.com/tgstation/tgstation/assets/8430839/ec6ff866-ef7d-4307-9d09-68df7900b6a5)

</details>
<details>
<summary>after</summary>
  

![image](https://github.com/tgstation/tgstation/assets/8430839/2459e00a-1c86-441a-87cd-afef99a63a7e)

</details>

## Why It's Good For The Game
always annoying when some random assistant calls cargo shuttle before
you finished ordering your stuff
## Changelog
:cl:
fix: fixed being able to confirm cargo orders from cargo request console
(and, probably, from PDAs)
/:cl:

tgui/packages/tgui/interfaces/Cargo/CargoCart.tsx

@@ -15,7 +15,7 @@ import { CargoData } from './types';
 
 export function CargoCart(props) {
   const { act, data } = useBackend<CargoData>();
-  const { requestonly, away, cart = [], docked, location } = data;
+  const { can_send, away, cart = [], docked, location } = data;
 
   const sendable = !!away && !!docked;
 
@@ -26,8 +26,8 @@ export function CargoCart(props) {
           <CheckoutItems />
         </Section>
       </Stack.Item>
-      <Stack.Item>
-        {cart.length > 0 && !requestonly && (
+      {cart.length > 0 && !!can_send && (
+        <Stack.Item>
           <Section align="right">
             <Stack fill align="center">
               <Stack.Item grow>
@@ -47,8 +47,8 @@ export function CargoCart(props) {
               </Stack.Item>
             </Stack>
           </Section>
-        )}
-      </Stack.Item>
+        </Stack.Item>
+      )}
     </Stack>
   );
 }