feat: merge upstream dev branch

- Add Gluetun dynamic VPN-to-HTTP proxy provider
   - Add remote services and authentication system
   - Add country code utilities
   - Add Docker binary detection
   - Update proxy providers

unshackle/core/binaries.py

@@ -52,6 +52,7 @@ Mkvpropedit = find("mkvpropedit")
 DoviTool = find("dovi_tool")
 HDR10PlusTool = find("hdr10plus_tool", "HDR10Plus_tool")
 Mp4decrypt = find("mp4decrypt")
+Docker = find("docker")
 
 
 __all__ = (
@@ -71,5 +72,6 @@ __all__ = (
     "DoviTool",
     "HDR10PlusTool",
     "Mp4decrypt",
+    "Docker",
     "find",
 )