### What type of PR is this?
/kind improvement
/area core
/milestone 2.13.x
### What this PR does / why we need it:
使用索引机制优化通知和订阅查询以提高性能
how to test it
测试通知列表不报错即可
### Does this PR introduce a user-facing change?
```release-note
使用索引机制优化通知和订阅查询以提高性能
```
#### What type of PR is this?
/kind feature
/kind improvement
/area core
/area console
/kind api-change
#### What this PR does / why we need it:
增加对用户注册时必须验证邮箱的支持
#### Which issue(s) this PR fixes:
Fixes#5016
#### Special notes for your reviewer:
`regRequireVerifyEmail` 为 `false` 时与现在的注册行为一致
为 `true` 时注册页显示验证码校验相关，注册成功后 `UserSpec.emailVerified` 即为 `true`
没有判断邮件通知是否开启，与现有的邮箱验证一致，如未开启则收不到邮件
#### Does this PR introduce a user-facing change?
```release-note
增加对用户注册时必须验证邮箱的支持
```
#### What type of PR is this?
/kind improvement
/area core
/milestone 2.13.x
#### What this PR does / why we need it:
使用索引功能优化附件列表查询
#### Does this PR introduce a user-facing change?
```release-note
使用索引功能优化附件列表查询
```
guqing