fix(module:cascader,select,time-picker,tooltip,tree-select): take in account shadow dom when getting the target of an event

[Lukinoh]

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?

If you have an ant component inside a ShadowDOM the function onClickOutside won't behave correctly.

I did a small stackblitz to showcase the issue.
You have 2 selects: One inside a ShadowDOM, and one without ShadowDOM.
If you spam click the select in the ShadowDOM version you will see that the list will appear twice, which is not the case with the one not using the ShadowDOM.

The issue is due to how event propagation is done with ShadowDOM.
Concretely, the function onClickOutside will receive as a target the ShadowRoot, and not the real clicked element.
To fix the issue you should take into account the ShadowDOM. Fortunately @angular/cdk/platform provides a function that does it which is _getEventTarget.

As a side note, here you have a great article that explain event propagation and shadow dom:
https://pm.dartus.fr/blog/a-complete-guide-on-shadow-dom-and-event-propagation/

What is the new behavior?

The behaviour will be exactly the same as today, however you won't have anymore a glitch when using your component inside a ShadowDOM.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

I am not sure how to test this.

[zorro-bot]

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[codecov]

Codecov Report

Attention: Patch coverage is 90.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 91.55%. Comparing base (710e20e) to head (5b2184e).
Report is 1 commits behind head on master.

Files	Patch %	Lines
components/time-picker/time-picker.component.ts	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7853      +/-   ##
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- Coverage   91.56%   91.55%   -0.01%     
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  Files         532      532              
  Lines       18337    18338       +1     
  Branches     2803     2803              
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  Hits        16790    16790              
- Misses       1229     1230       +1     
  Partials      318      318              

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[Laffery]

LGTM