fix: clear value when format is function

[kerm1it]

之前只是禁止 input 输入，但是忘了清除的时候还是会走解析值的逻辑。

[vercel]

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[codecov]

Codecov Report

Merging #144 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #144   +/-   ##
=======================================
  Coverage   99.59%   99.59%           
=======================================
  Files          45       45           
  Lines        1994     1998    +4     
  Branches      586      587    +1     
=======================================
+ Hits         1986     1990    +4     
  Misses          6        6           
  Partials        2        2           

Impacted Files	Coverage Δ
src/Picker.tsx	100.00% <100.00%> (ø)
src/RangePicker.tsx	100.00% <100.00%> (ø)
src/utils/dateUtil.ts	100.00% <100.00%> (ø)

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