fix(input-number): many fixes

[07akioni]

• Fix n-input-number lacks on-update-value prop.
• Fix n-input-number's value can't be null.
• Fix n-input-number's button doesn't work after value is cleared, closes #251.
• n-input-number will focus directly, closes #244.

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[codecov]

Codecov Report

Merging #259 (a91dd59) into main (fd23a30) will increase coverage by 0.57%.
The diff coverage is 63.63%.

❗ Current head a91dd59 differs from pull request most recent head 0d21a73. Consider uploading reports for the commit 0d21a73 to get more accurate results

@@            Coverage Diff             @@
##             main     #259      +/-   ##
==========================================
+ Coverage   31.35%   31.92%   +0.57%     
==========================================
  Files         505      505              
  Lines       12001    12005       +4     
  Branches     3264     3266       +2     
==========================================
+ Hits         3763     3833      +70     
+ Misses       7546     7451      -95     
- Partials      692      721      +29     

Impacted Files	Coverage Δ
src/input-number/src/InputNumber.tsx	53.17% <63.63%> (+15.90%)	⬆️
src/_mixins/use-form-item.ts	57.69% <0.00%> (ø)
src/input/src/Input.tsx	31.90% <0.00%> (+11.51%)	⬆️
src/input-number/src/utils.ts	73.33% <0.00%> (+40.00%)	⬆️

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