feat: add placeholder option for multiple picker

[nova1751]

Related to ant-design/ant-design#47665. I add placeholder support for multiple date-picker, just like the rc-select component.

[vercel]

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Name	Status	Preview	Comments	Updated (UTC)
picker	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 10, 2024 1:24pm

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.58%. Comparing base (ac9c87b) to head (a400d54).
Report is 3 commits behind head on master.

❗ Current head a400d54 differs from pull request most recent head b9ebab5. Consider uploading reports for the commit b9ebab5 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #768   +/-   ##
=======================================
  Coverage   98.58%   98.58%           
=======================================
  Files          63       63           
  Lines        2542     2544    +2     
  Branches      701      677   -24     
=======================================
+ Hits         2506     2508    +2     
  Misses         33       33           
  Partials        3        3           

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[nova1751]

Hello, can anyone review the code? @zombieJ @afc163

[nova1751]

@zombieJ Hello, I think this PR solved the placeholder problem issue ant-design/ant-design#47665 mentioned. Could you review the code if you have time or should I close this PR?

[afc163]

@zombieJ @MadCcc

[toFrankie]

有进展否？👀

[zombieJ]

OPS. Sorry I miss this PR. I've updated in #798 😂

[nova1751]

OPS. Sorry I miss this PR. I've updated in #798 😂

OK, waste a little time, though😂