* Proxy: TUN: Enhance Darwin interface support.
- reduce number of actions done to create/configure the interface in the system
- assign synthetic static link-local ipv4/ipv6 addresses to the interface, that are required by the OS for the routing to work
- make tun_darwin_endpoint be implemented significantly more similar to tun_windows_enpoint, preparing them for potential unification
* Proxy: TUN: Unify Darwin/Windows endpoint, which are now extremely similar, into one GVisorEndpoint.
Making darwin/windows tun implement GVisorDevice with simple readpacket/writepacket methods that GVisorEndpoint untilise
* Proxy: Implement tun raw network interface inbound support for Linux
* Proxy: Tun. Include "android" as build condition for build of tun_default implementation
* Proxy: Tun. Add .Close() cleanup calls to Handler.Init() where needed
* Proxy: Add Tun for Android
* Proxy: Tun. Implement Windows support
---------
Co-authored-by: yuhan6665 <1588741+yuhan6665@users.noreply.github.com>
