feat:add single party func abs

[cs1317]

在SCQL中实现单方算子abs
#112

[github-actions]

CLA Assistant Lite bot:
Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

---

I have read the CLA Document and I hereby sign the CLA

---

1 out of 2 committers have signed the CLA.
✅ @cs1317
❌ @chengsai1
chengsai1 seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You can retrigger this bot by commenting recheck in this Pull Request}

[tongke6]

@cs1317 please sign the CLA

[cs1317]

I have read the CLA Document and I hereby sign the CLA

[tongke6]

LGTM

[tongke6]

@cs1317 你好，CLA check 一直没过，应该和第一个 commit 的作者信息不对有关系，麻烦看下如何解决