Record TagType when decoding RawMessage.

Display item's NBT in example/daze.
Upgrade data/item to 1.17

nbt/rawmsg.go

@@ -3,6 +3,7 @@ package nbt
 import (
 	"bytes"
 	"io"
+	"strings"
 )
 
 type RawMessage struct {
@@ -29,6 +30,22 @@ func (m *RawMessage) Decode(tagType byte, r DecoderReader) error {
 	if err != nil {
 		return err
 	}
+	m.Type = tagType
 	m.Data = buf.Bytes()
 	return nil
 }
+
+func (m RawMessage) String() string {
+	if m.Type == TagEnd {
+		return "TagEnd"
+	}
+	var snbt StringifiedMessage
+	var sb strings.Builder
+	r := bytes.NewReader(m.Data)
+	d := NewDecoder(r)
+	err := snbt.encode(d, &sb, m.Type)
+	if err != nil {
+		return "Invalid"
+	}
+	return sb.String()
+}