fix(module:select): change order for clear and arrow

[rencoo]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NG-ZORRO/ng-zorro-antd/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

can clear content when clear and arrow icon overlap in nz-select component

Issue Number: N/A
#5989

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[zorro-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

Merging #6245 (b7d8a27) into master (a4dbe23) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6245      +/-   ##
==========================================
- Coverage   89.80%   89.79%   -0.02%     
==========================================
  Files         477      477              
  Lines       15186    15186              
  Branches     2298     2298              
==========================================
- Hits        13638    13636       -2     
- Misses        949      951       +2     
  Partials      599      599              

Impacted Files	Coverage Δ
components/select/select.component.ts	87.86% <ø> (ø)
components/tabs/tab-nav-bar.component.ts	81.69% <0.00%> (-0.71%)	⬇️

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[wenqi73]

@rencoo Thanks!