Disable configuration of vanilla WG clients

[teon]

In the Settings "Enterprise features" tab add a "toggle" for enabling/disabling users the ability to configure vanilla (manual) clients.

If ability to configure vanilla/manual clients is disabled:

• [x] We skip the screen when choosing which type of client the user wants to configure (defguard/manual) and go straight to defguard client configuration
• [x] On the defguard client configuration screen, since there is just the URL and token, we need to add the following information as help above:

Please download defguard desktop client [here](https://defguard.net/download),
then follow [this guide](https://defguard.gitbook.io/defguard/help/configuring-vpn/add-new-instance) to configure your client.