DoH proxy: https-dns-proxy new RFC8484-supporting package and Web UI

[Aisfkhan]

@stangri

@Aisfkhan thanks for reporting, this was fixed in 2026.03.18-r2. There are additional improvements that @egc112egc112 implemented after that, so I’ll likely push 2026.03.18-r3 into snapshots and release OpenWrt repos before the end of the week.

Installed R2 from GitHub — everything is working perfectly now.
Using https-dns-proxy, adblock-fast, and PBR together with great results. Thanks for your contributions to OpenWrt!