支持拉黑，屏蔽群成员私聊

cooleshow-app/src/main/java/com/yonge/cooleshow/student/controller/ImGroupController.java

@@ -64,6 +64,7 @@ public class ImGroupController extends BaseController {
         ImGroupMember admin = imGroupMemberService.lambdaQuery()
                 .eq(ImGroupMember::getGroupId, group.getId())
                 .eq(ImGroupMember::getUserId, userId)
+                .eq(ImGroupMember::getRoleType, ImGroupMemberRoleType.STUDENT)
                 .last("limit 1").one();
         if (admin == null) {
             // 该用户不在该群，无权限查看，处理用户退出群后，查看历史消息校验

cooleshow-app/src/main/java/com/yonge/cooleshow/teacher/controller/ImGroupController.java

@@ -140,6 +140,7 @@ public class ImGroupController extends BaseController {
         }
         ImGroupMember admin = imGroupMemberService.lambdaQuery()
                 .eq(ImGroupMember::getGroupId, group.getId())
+                .eq(ImGroupMember::getRoleType, ImGroupMemberRoleType.TEACHER)
                 .eq(ImGroupMember::getUserId, sysUserService.getUser().getId())
                 .last("limit 1").one();
         if (admin == null) {