feature: add ShortVideo message support

mirai-core/src/commonMain/kotlin/message/data/shortVideo.kt

@@ -101,11 +101,16 @@ internal class OnlineShortVideoMsgInternal(
     }
 }
 
+@Serializable
+internal class ShortVideoThumbnail(
+    val md5: ByteArray,
+    val size: Long,
+    val width: Int?,
+    val height: Int?,
+)
+
 internal abstract class AbstractShortVideoWithThumbnail : ShortVideo {
-    abstract val thumbMd5: ByteArray
-    abstract val thumbSize: Long
-    abstract val thumbWidth: Int?
-    abstract val thumbHeight: Int?
+    abstract val thumbnail: ShortVideoThumbnail
 }
 
 @Suppress("DuplicatedCode")
@@ -118,11 +123,14 @@ internal class OnlineShortVideoImpl(
     override val fileSize: Long,
     override val fileFormat: String,
     override val urlForDownload: String,
-    override val thumbMd5: ByteArray,
-    override val thumbSize: Long,
-    @Transient override val thumbWidth: Int = 0,
-    @Transient override val thumbHeight: Int = 0
+    val thumbMd5: ByteArray,
+    val thumbSize: Long,
+    @Transient val thumbWidth: Int = 0,
+    @Transient val thumbHeight: Int = 0
 ) : OnlineShortVideo, AbstractShortVideoWithThumbnail() {
+    override val thumbnail: ShortVideoThumbnail by lazy {
+        ShortVideoThumbnail(thumbMd5, thumbSize, thumbWidth, thumbHeight)
+    }
 
     override fun toString(): String {
         return "[mirai:shortvideo:$videoId, videoName=$filename.$fileFormat, videoMd5=${fileMd5.toUHexString("")}, " +
@@ -175,11 +183,14 @@ internal class OfflineShortVideoImpl(
     override val fileMd5: ByteArray,
     override val fileSize: Long,
     override val fileFormat: String,
-    override val thumbMd5: ByteArray,
-    override val thumbSize: Long,
-    @Transient override val thumbWidth: Int = 0,
-    @Transient override val thumbHeight: Int = 0
+    val thumbMd5: ByteArray,
+    val thumbSize: Long,
+    @Transient val thumbWidth: Int = 0,
+    @Transient val thumbHeight: Int = 0
 ) : OfflineShortVideo, AbstractShortVideoWithThumbnail() {
+    override val thumbnail: ShortVideoThumbnail by lazy {
+        ShortVideoThumbnail(thumbMd5, thumbSize, thumbWidth, thumbHeight)
+    }
 
     /**
      * offline short video uses

mirai-core/src/commonMain/kotlin/message/protocol/impl/ShortVideoProtocol.kt

@@ -51,8 +51,8 @@ internal class ShortVideoProtocol : MessageProtocol() {
 
             collect(ImMsgBody.Elem(text = ImMsgBody.Text("你的 QQ 暂不支持查看视频短片，请期待后续版本。")))
 
-            val thumbWidth = if (data.thumbWidth == null || data.thumbWidth == 0) 1280 else data.thumbWidth!!
-            val thumbHeight = if (data.thumbHeight == null || data.thumbHeight == 0) 720 else data.thumbHeight!!
+            val thumbWidth = if (data.thumbnail.width == null || data.thumbnail.width == 0) 1280 else data.thumbnail.width!!
+            val thumbHeight = if (data.thumbnail.height == null || data.thumbnail.height == 0) 720 else data.thumbnail.height!!
 
             collect(
                 ImMsgBody.Elem(
@@ -65,8 +65,8 @@ internal class ShortVideoProtocol : MessageProtocol() {
                         fileSize = data.fileSize.toInt(),
                         thumbWidth = thumbWidth,
                         thumbHeight = thumbHeight,
-                        thumbFileMd5 = data.thumbMd5,
-                        thumbFileSize = data.thumbSize.toInt(),
+                        thumbFileMd5 = data.thumbnail.md5,
+                        thumbFileSize = data.thumbnail.size.toInt(),
                         busiType = 0,
                         fromChatType = -1,
                         toChatType = -1,