Feat twitch livestreams (#334)

* backend code

* fixed twitch authentication

server/middleware/utils.go

@@ -0,0 +1,20 @@
+package middlewares
+
+import (
+	"net/http"
+
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/config"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/openid"
+)
+
+func ApplyAuthenticationByConfig(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if config.Instance().RequireAuth {
+			Authenticated(next)
+		}
+		if config.Instance().UseOpenId {
+			openid.Middleware(next)
+		}
+		next.ServeHTTP(w, r)
+	})
+}