[#1054] network: Optimize IsTLSEnabled()

No big deal, but it is called multiple times in sorting routine, this
easily results in 20 allocations per group traversal.

```
goos: linux
goarch: amd64
pkg: git.frostfs.info/TrueCloudLab/frostfs-node/pkg/network
cpu: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
                    │     old     │                 new                 │
                    │   sec/op    │   sec/op     vs base                │
AddressTLSEnabled-8   184.6n ± 1%   103.3n ± 6%  -44.04% (p=0.000 n=10)

                    │    old     │                new                │
                    │    B/op    │   B/op    vs base                 │
AddressTLSEnabled-8   704.0 ± 0%   0.0 ± 0%  -100.00% (p=0.000 n=10)

                    │    old     │                 new                 │
                    │ allocs/op  │ allocs/op   vs base                 │
AddressTLSEnabled-8   1.000 ± 0%   0.000 ± 0%  -100.00% (p=0.000 n=10)
```

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/network/tls.go

@@ -13,11 +13,6 @@ var tls, _ = multiaddr.NewMultiaddr("/" + tlsProtocolName)
 
 // IsTLSEnabled searches for wrapped TLS protocol in multiaddr.
 func (a Address) IsTLSEnabled() bool {
-	for _, protoc := range a.ma.Protocols() {
-		if protoc.Code == multiaddr.P_TLS {
-			return true
-		}
-	}
-
-	return false
+	_, err := a.ma.ValueForProtocol(multiaddr.P_TLS)
+	return err == nil
 }

pkg/network/tls_test.go

@@ -27,3 +27,18 @@ func TestAddress_TLSEnabled(t *testing.T) {
 		require.Equal(t, test.wantTLS, addr.IsTLSEnabled(), test.input)
 	}
 }
+
+func BenchmarkAddressTLSEnabled(b *testing.B) {
+	var addr Address
+	err := addr.FromString("/dns4/localhost/tcp/8080/tls")
+	require.NoError(b, err)
+
+	b.ResetTimer()
+	b.ReportAllocs()
+
+	var enabled bool
+	for i := 0; i < b.N; i++ {
+		enabled = addr.IsTLSEnabled()
+	}
+	require.True(b, enabled)
+}