Improve logging

- Actually log useful information at their respective log level.
- Add logs in hot-paths to be able to deep-dive and debug specific
requests (see server/handler.go)
- Remove zerologger and instead use custom logger that doesn't log
JSON (directly inspired by https://codeberg.org/Codeberg/moderation/pulls/7).
- Add more information to existing fields(e.g. the host that the user is
visiting, this was noted by @fnetX).

integration/main_test.go

@@ -5,25 +5,25 @@ package integration
 
 import (
 	"context"
+	"log"
 	"os"
 	"testing"
 	"time"
 
 	"codeberg.org/codeberg/pages/cmd"
 
-	"github.com/rs/zerolog/log"
 	"github.com/urfave/cli/v2"
 )
 
 func TestMain(m *testing.M) {
-	log.Printf("=== TestMain: START Server ===\n")
+	log.Println("=== TestMain: START Server ===")
 	serverCtx, serverCancel := context.WithCancel(context.Background())
 	if err := startServer(serverCtx); err != nil {
 		log.Fatal().Msgf("could not start server: %v", err)
 	}
 	defer func() {
 		serverCancel()
-		log.Printf("=== TestMain: Server STOPED ===\n")
+		log.Println("=== TestMain: Server STOPED ===")
 	}()
 
 	time.Sleep(10 * time.Second)