feat(editor): 新增课程批量操作功能并优化界面样式

- 添加全选、批量删除、复制选中课程等功能
- 实现课程行上下移动功能

Author: dongkid

constants.py

@@ -8,5 +8,5 @@
 # 程序信息
 APP_NAME = "桌面课程表 - Course Scheduler"
 AUTHOR = "dong"
-VERSION = "0.1.14"
+VERSION = "0.1.15beta"
 PROJECT_URL = "https://github.com/dongkid/course_scheduler"