Feat livestream support (#180)

* experimental livestrea support

* test livestream

* update wait time detection

* update livestream functions

* persist and restore livestreams monitor session

* fan-in logging

* deps update

* added live time display

* livestream monitor prototype

* changed to default logger instead of passing *slog.Logger everywhere

* code refactoring, comments

server/internal/livestream/livestream_test.go

@@ -0,0 +1,36 @@
+package livestream
+
+import (
+	"testing"
+	"time"
+
+	"github.com/marcopeocchi/yt-dlp-web-ui/server/config"
+)
+
+func setupTest() {
+	config.Instance().DownloaderPath = "yt-dlp"
+}
+
+func TestLivestream(t *testing.T) {
+	setupTest()
+
+	done := make(chan *LiveStream)
+	log := make(chan []byte)
+
+	ls := New("https://www.youtube.com/watch?v=LSm1daKezcE", log, done)
+	go ls.Start()
+
+	time.AfterFunc(time.Second*20, func() {
+		ls.Kill()
+	})
+
+	for {
+		select {
+		case wt := <-ls.WaitTime():
+			t.Log(wt)
+		case <-done:
+			t.Log("done")
+			return
+		}
+	}
+}