Nexo Hosting Panel -- WHMCS server module 1.0.0

Lets WHMCS create, suspend, unsuspend, terminate and re-plan hosting accounts on your Nexo server,
change the customer's password, read disk usage, and sign the customer straight into their
control panel from the client area.

Install
1. Copy modules/servers/nexo/ into your WHMCS folder (so you have <whmcs>/modules/servers/nexo/nexo.php).
2. In Nexo, open Administration > API and make a key. Under "Allowed from", give your WHMCS
   server's address. Copy the key (it starts with nxk_); it is shown once.
3. In WHMCS: System Settings > Servers > Add New Server.
   Module: Nexo Panel. Hostname: your Nexo server's name. Password: the key.
   Port: 2083 (unless you changed it). Tick "Secure". Test Connection should succeed.
4. Products/Services: on each hosting product, Module Settings > Module: Nexo Panel,
   then pick the Nexo plan the product sells.

The module finds an account by the service's domain, so keep the domain in WHMCS the same
as the account's. Every call is in WHMCS's module log, with the key and passwords masked.

Needs Nexo 1.2.9 or later and PHP 7.4+ with cURL.
