fix(comp:alert): style update

[danranVm]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines
• Tests for the changes have been added/updated or not needed
• Docs and demo have been added/updated or not needed

What is the current behavior?

What is the new behavior?

• 默认的 padding 8px, banner 模式下的 padding 16px
• 新增了一个超长文本轮播的 demo

Other information

[idux-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

Merging #1377 (04efc14) into main (8dbee09) will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #1377      +/-   ##
==========================================
- Coverage   92.89%   92.86%   -0.03%     
==========================================
  Files         324      324              
  Lines       29851    29845       -6     
  Branches     2474     2474              
==========================================
- Hits        27730    27717      -13     
- Misses       2121     2128       +7     

Impacted Files	Coverage Δ
packages/components/dropdown/src/Dropdown.tsx	40.00% <0.00%> (-19.38%)	⬇️
packages/components/cascader/src/Cascader.tsx	95.87% <0.00%> (+0.02%)	⬆️
packages/components/tree-select/src/TreeSelect.tsx	95.47% <0.00%> (+0.02%)	⬆️
packages/components/select/src/Select.tsx	87.12% <0.00%> (+0.05%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.