Add vpn support natively in cloudstream

[NivinCNC]

Added native vpn support. But need some suggestions in cronet since it obeys only system wide proxy and doest support proxy itself

[fire-light42]

Please see our AI policy.

Proxy support could work in CloudStream, but this implementation is very bloated. Ideally the implementation should be about ±100 lines (tests should be separated). Additionally, the references to VPNs are misleading, this feature should be advertised (and programmed) as proxy support, even if users only know what a VPN is.

[NivinCNC]

I admit this code is by ai and sorry for not mentioning it, i just wanna outline the vpn implementation and standardize it later, since i wanted to know wheter disabling cronet if vpn is enabled is okai or not. If that's confirmed, i can provide a quality code at my level best.

[fire-light42]

Yes, Cronet may be disabled when a proxy is enabled, we already disable it whenever interceptors are used 👍

It is preferable if Cronet can be made compatible, but I understand that it may not be possible.