chore(module:date-picker,time-picker): prevent losing input focus

[wenqi73]

close #6170

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?

[ ] 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
[x] Other... Please describe:

What is the current behavior?

Issue Number: N/A

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 #6171 (6859ac9) into master (51c4cb2) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #6171      +/-   ##
==========================================
- Coverage   89.84%   89.82%   -0.02%     
==========================================
  Files         468      468              
  Lines       14255    14259       +4     
  Branches     2242     2242              
==========================================
+ Hits        12807    12808       +1     
- Misses        892      895       +3     
  Partials      556      556              

Impacted Files	Coverage Δ
...mponents/date-picker/date-range-popup.component.ts	90.80% <0.00%> (-1.06%)	⬇️
...ponents/time-picker/time-picker-panel.component.ts	89.02% <0.00%> (-0.73%)	⬇️
components/time-picker/time-holder.ts	94.73% <0.00%> (-1.06%)	⬇️
components/core/util/text-measure.ts	91.30% <0.00%> (+1.73%)	⬆️

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