Fix int types in OpenSubsonic responses.

Refer to https://support.symfonium.app/t/symfonium-sync-crashes-when-tpos-is-not-an-int/4204

utils/number/number.go

@@ -3,9 +3,17 @@ package number
 import (
 	"crypto/rand"
 	"math/big"
+	"strconv"
+
+	"golang.org/x/exp/constraints"
 )
 
 func RandomInt64(max int64) int64 {
 	rnd, _ := rand.Int(rand.Reader, big.NewInt(max))
 	return rnd.Int64()
 }
+
+func ParseInt[T constraints.Integer](s string) T {
+	r, _ := strconv.ParseInt(s, 10, 64)
+	return T(r)
+}