common/embed: add a benchmark for reading from embed.zip

This is slower, but it seems reasonable:

```
goos: linux
goarch: amd64
pkg: akvorado/common/embed
cpu: AMD Ryzen 5 5600X 6-Core Processor
BenchmarkData/compressed-12         	    2262	    526553 ns/op	     610 B/op	      10 allocs/op
BenchmarkData/uncompressed-12       	    9482	    123175 ns/op	       0 B/op	       0 allocs/op
```

common/embed/fs_test.go

@@ -1,21 +1,26 @@
 // SPDX-FileCopyrightText: 2025 Free Mobile
 // SPDX-License-Identifier: AGPL-3.0-only
 
-package embed_test
+package embed
 
 import (
+	_ "embed"
 	"io"
 	"testing"
 
-	"akvorado/common/embed"
 	"akvorado/common/helpers"
 )
 
 func TestData(t *testing.T) {
-	f, err := embed.Data().Open("orchestrator/clickhouse/data/protocols.csv")
+	f, err := Data().Open("orchestrator/clickhouse/data/protocols.csv")
 	if err != nil {
 		t.Fatalf("Open() error:\n%+v", err)
 	}
+	defer func() {
+		if err := f.Close(); err != nil {
+			t.Fatalf("Close() error:\n%+v", err)
+		}
+	}()
 	expected := "proto,name,description"
 	got := make([]byte, len(expected))
 	_, err = io.ReadFull(f, got)
@@ -26,3 +31,21 @@ func TestData(t *testing.T) {
 		t.Fatalf("ReadFull() (-got, +want):\n%s", diff)
 	}
 }
+
+func BenchmarkData(b *testing.B) {
+	const amount = 64 * 1024 * 1024
+	got := make([]byte, amount)
+	b.Run("compressed", func(b *testing.B) {
+		for b.Loop() {
+			f, _ := Data().Open("orchestrator/clickhouse/data/tcp.csv")
+			_, _ = io.ReadFull(f, got)
+			f.Close()
+		}
+	})
+	b.Run("uncompressed", func(b *testing.B) {
+		for b.Loop() {
+			copy(got, embeddedZip)
+		}
+	})
+
+}