fix: multi value should handle undefined

[MadCcc]

• fix: add null check for multi-value
• chore: add test
• chore: add more check

[github-actions[bot]]

😭 Deploy PR Preview 814243df68e74e73a8e94242eb55ad7b462ffd6d failed. Build logs

_{🤖 By surge-preview}

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.03 :tada:

Comparison is base (359b29d) 92.98% compared to head (d84a3cb) 93.01%.

:exclamation: Current head d84a3cb differs from pull request most recent head 814243d. Consider uploading reports for the commit 814243d to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #108 +/- ## ========================================== + Coverage 92.98% 93.01% +0.03% ========================================== Files 19 19 Lines 627 630 +3 Branches 208 211 +3 ========================================== + Hits 583 586 +3 Misses 44 44 ``` | [Impacted Files](https://codecov.io/gh/ant-design/cssinjs/pull/108?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design) | Coverage Δ | | |---|---|---| | [src/hooks/useStyleRegister.tsx](https://codecov.io/gh/ant-design/cssinjs/pull/108?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design#diff-c3JjL2hvb2tzL3VzZVN0eWxlUmVnaXN0ZXIudHN4) | `98.81% <100.00%> (+0.02%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design)

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