fix(form): fix transformKeySubmitValue will gen null value error

[chenshuai2144]

close #2570

[github-actions]

🎊 PR Preview has been successfully built and deployed to https://pro-components-preview-pr-2571.surge.sh

[lgtm-com]

This pull request introduces 1 alert when merging 7497208 into 7f0cab6 - view on LGTM.com

new alerts:

• 1 for Unneeded defensive code

[github-actions]

size-limit report

Path	Size
packages/card/dist/card.js	19.08 KB (0%)
packages/descriptions/dist/descriptions.js	20.71 KB (0%)
packages/field/dist/field.js	133.1 KB (0%)
packages/form/dist/form.js	60.89 KB (0%)
packages/layout/dist/layout.js	88.6 KB (0%)
packages/list/dist/list.js	142.24 KB (0%)
packages/provider/dist/provider.js	11.74 KB (0%)
packages/skeleton/dist/skeleton.js	5.19 KB (0%)
packages/table/dist/table.js	47.67 KB (0%)

[codecov]

Codecov Report

Merging #2571 (7497208) into master (7f0cab6) will decrease coverage by 0.01%.
The diff coverage is 50.00%.

❗ Current head 7497208 differs from pull request most recent head c2c37c1. Consider uploading reports for the commit c2c37c1 to get more accurate results

@@            Coverage Diff             @@
##           master    #2571      +/-   ##
==========================================
- Coverage   99.14%   99.12%   -0.02%     
==========================================
  Files         171      171              
  Lines        5138     5140       +2     
  Branches     1847     1848       +1     
==========================================
+ Hits         5094     5095       +1     
- Misses         43       44       +1     
  Partials        1        1              

Impacted Files	Coverage Δ
...ackages/utils/src/transformKeySubmitValue/index.ts	97.56% <50.00%> (-2.44%)	⬇️

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[lgtm-com]

This pull request introduces 1 alert when merging c2c37c1 into 7f0cab6 - view on LGTM.com

new alerts:

• 1 for Unneeded defensive code