消息列表和聊天时调整

app/src/main/java/com/aiosman/ravenow/entity/Group.kt

@@ -0,0 +1,16 @@
+package com.aiosman.ravenow.entity
+
+data class GroupMember(
+    val userId: String,
+    val nickname: String,
+    val avatar: String,
+    val isOwner: Boolean = false
+)
+
+data class GroupInfo(
+    val groupId: String,
+    val groupName: String,
+    val groupAvatar: String,
+    val memberCount: Int,
+    val members: List<GroupMember>
+)