[Frontend] Add total number of pages

[dpang314]

Description

• When viewing a list of users, we should show the max number of pages

Acceptance Criteria

• Modify the current page number so that the format is "[current page #]/[maximum pages]"
• The max number of pages will need to be passed in as a prop

Other Notes

• mobile/components/Overlays/PaginatedOverlay.tsx
• Modify the adminGetUsers function in mobile/screens/Admin/AdminUserListScreen.tsx so that the API response is in the format of

{
   users: Users[],
   total: number,
}

• You will need to change all locations where adminGetUsers is called using ErrorWrapper
• This backend change will be implemented in a separate ticket, you can use dummy data while testing