Add tvOS support

[DandelionSprout]

Issue Details

I'm in a very, very, very specifically narrow situation where tvOS support for AdGuard VPN would make perfect sense:

1. My secretary has a subscription to HBO-Discovery Max, which I borrow so I can watch Teen Titans GO and FIA WEC.
2. My smart-TV is (according to Max) too old (2016 LG model) to even be allowed to install Max.
3. Despite Max bragging about 4K on supported devices, they don't like web browsers (Chrome or Firefox) or Telenor Norway's T-We Boks set-top boxes very much, which they limit to 720p, which made Le Mans look a little like porridge.
4. Disney+ hates me on a personal level, because they block all publicly known Tor server IPs (of which I run one or two) even at my home in supported countries like Norway.
5. Netflix complains to me about "not being in the correct household" on my LG TV and T-We Boks for my secretary's subscription as well. (Web browsers and PS3 can however handle 1080p with no household limits, but not 4K without massive loopholes.)
6. I'd therefore want functional VPN on tvOS before I'd commit to 200€ for an Apple TV 4K 128GB (The 64GB model lacks Ethernet for some reason).
7. My pa's PlayStation 5 can't handle 50Hz livestreams correctly, resulting in easily noticeable jarring on Max's European simulcasts with Eurosport of sports events, incl. Le Mans.
8. I don't really want to buy a Chromecast, Amazon Fire TV, or a new TV, because their remote controls all have "very old people or toddlers" buttons that have Netflix and Prime instant entry buttons, but very often not any normal buttons like Play/Pause or Settings.
9. Buying an Xbox 2016-onwards model would've required https://github.com/AdguardTeam/AdGuardVPNForWindows to extend support to Microsoft Store.

While the topic has been brought up before on AdguardTeam/AdGuardVPNForMac#142, it doesn't appear like the plans went as well as it was hoped for at the time.

Proposed solution

https://apps.apple.com/ie/app/adguard-vpn-unlimited-fast/id1525373602 should be extended to support tvOS. (I had honestly never heard of visionOS before I checked App Store, so if visionOS can get supported then tvOS can't be impossible either.)

Alternative solution

https://github.com/AdguardTeam/AdGuardVPNForWindows should be extended to support Xbox One/Series on Microsoft Store (AdguardTeam/AdGuardVPNForWindows#696). I admit it'd be difficult, but it is a perfectly fair alternative solution.

As a 3rd option, I would be able to run a proxy from my AdGuard (VPN) for Windows paid subscription with some difficulty, but it feels imfeasibly impractical to me, and doesn't feel like something I'd commit to before buying any devices.

[Versty]

@DandelionSprout, Hi!
We have certain plans on developing AdGuard VPN for tvOS in the future. However, we have a solution that is already available - AdGuard VPN for routers. If your router supports IPSec, this software will fit perfectly, highly recommend giving it a try!

[yariksmirnov]

Actually not so many routers support IPSec (not L2TP). OpenVPN / Wireguard are more frequent options. I've just bought a bleeding-edge new router Archer AX80 and I could not imaging that I will face protocol compatibility problem.

VPN on router is better that nothing, but you should have really specific setup to be able to use it.
As YouTube is now blocked in Russia, I need VPN specifically in AppleTV.
I will try to write my own NetworkExtension for tvOS using IPSec credentials for router. If I wouldn't manage I will be forced to move to NordVPN with native app on AppleTV and OpenVPN protocol for router support