feat(inputNumber): add NInputNumber slots

[XieZongChen]

closes #609

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/tusimple/naive-ui/GT45drtdiid8RSHG11MeAKT9mCyt
✅ Preview: https://naive-ui-git-fork-amadeus711-feat-add-ninputnum-9f6612-tusimple.vercel.app

[codecov]

Codecov Report

Merging #626 (f161df6) into main (f12d408) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head f161df6 differs from pull request most recent head 7fb804a. Consider uploading reports for the commit 7fb804a to get more accurate results

@@            Coverage Diff             @@
##             main     #626      +/-   ##
==========================================
+ Coverage   39.08%   39.09%   +0.01%     
==========================================
  Files         507      507              
  Lines       12310    12309       -1     
  Branches     3431     3431              
==========================================
+ Hits         4811     4812       +1     
+ Misses       6594     6593       -1     
+ Partials      905      904       -1     

Impacted Files	Coverage Δ
src/input/src/styles/input.cssr.ts	100.00% <ø> (ø)
src/input-number/src/InputNumber.tsx	52.90% <100.00%> (-0.28%)	⬇️
src/input/src/Input.tsx	37.37% <0.00%> (+0.65%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f12d408...7fb804a. Read the comment docs.