Add sequenceId to MessageSource

mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/message/MessageSourceFromMsg.kt

@@ -22,6 +22,7 @@ internal inline class MessageSourceFromServer(
     val delegate: ImMsgBody.SourceMsg
 ) : MessageSource {
     override val time: Long get() = delegate.time.toLong() and 0xFFFFFFFF
+    override val sequenceId: Int get() = delegate.origSeqs?.firstOrNull() ?: error("cannot find sequenceId from ImMsgBody.SourceMsg")
     override val messageUid: Long get() = delegate.pbReserve.loadAs(SourceMsg.ResvAttr.serializer()).origUids!!
     override val sourceMessage: MessageChain get() = delegate.toMessageChain()
     override val senderId: Long get() = delegate.senderUin
@@ -34,6 +35,7 @@ internal inline class MessageSourceFromMsg(
     val delegate: MsgComm.Msg
 ) : MessageSource {
     override val time: Long get() = delegate.msgHead.msgTime.toLong() and 0xFFFFFFFF
+    override val sequenceId: Int get() = delegate.msgHead.msgSeq
     override val messageUid: Long get() = delegate.msgBody.richText.attr!!.random.toLong()
     override val sourceMessage: MessageChain get() = delegate.toMessageChain()
     override val senderId: Long get() = delegate.msgHead.fromUin

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/message/data/MessageSource.kt

@@ -26,6 +26,11 @@ import kotlin.jvm.JvmName
 interface MessageSource : Message {
     companion object Key : Message.Key<MessageSource>
 
+    /**
+     * 序列号
+     */
+    val sequenceId: Int
+
     /**
      * 实际上是个随机数, 但服务器确实是用它当做 uid
      */