[Admin] Queued API call during writing order history in POS page

[somnisomni]

• When clicking the "Confirm order" button on the POS page, the API call should be queued instead of a direct call.
• When any API call is queued in the queue, process them sequentially.
• API call queue should be defined and processed app-globally, not in the page component, to prevent queued API calls from being canceled and deleted after leaving the POS page.
• This will improve API call reliability on low-quality networks like the mobile network in crowded event halls.