Allow URLs up to 32KB and improve parsing speed (#20874)

Before/after...
```
Benchmark_hasBadPathComponent/long-32          	   43936	     27232 ns/op	 146.89 MB/s	   32768 B/op	       1 allocs/op
Benchmark_hasBadPathComponent/long-32          	   89956	     13375 ns/op	 299.07 MB/s	       0 B/op	       0 allocs/op
```

* Remove unused.

cmd/generic-handlers_test.go

@@ -22,6 +22,7 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"strconv"
+	"strings"
 	"testing"
 
 	"github.com/minio/minio/internal/crypto"
@@ -184,3 +185,27 @@ func TestSSETLSHandler(t *testing.T) {
 		}
 	}
 }
+
+func Benchmark_hasBadPathComponent(t *testing.B) {
+	tests := []struct {
+		name  string
+		input string
+		want  bool
+	}{
+		{name: "empty", input: "", want: false},
+		{name: "backslashes", input: `\a\a\ \\  \\\\\\\`, want: false},
+		{name: "long", input: strings.Repeat("a/", 2000), want: false},
+		{name: "long-fail", input: strings.Repeat("a/", 2000) + "../..", want: true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(b *testing.B) {
+			b.SetBytes(int64(len(tt.input)))
+			b.ReportAllocs()
+			for i := 0; i < b.N; i++ {
+				if got := hasBadPathComponent(tt.input); got != tt.want {
+					t.Fatalf("hasBadPathComponent() = %v, want %v", got, tt.want)
+				}
+			}
+		})
+	}
+}