Get-CopilotBilling - update new api information

[rulasg]

APi has changed and we need to read the new information correctly

{
  "seat_breakdown": {
    "total": 45,
    "added_this_cycle": 0,
    "pending_invitation": 0,
    "pending_cancellation": 0,
    "active_this_cycle": 17,
    "inactive_this_cycle": 28
  },
  "seat_management_setting": "assign_selected",
  "public_code_suggestions": "allow",
  "ide_chat": "enabled",
  "cli": "enabled",
  "platform_chat": "enabled"
}