fix(module:modal): change back to FocusTrapFactory

[rppig42]

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?

#5591

the new introduced ConfigurableFocusTrapFactory strategy disables clicks outside overlay, which is not compatible with many third-party libraries.

Literally, FocusTrap should only prevent focus event other than click event.

On the other hand, even Angular Material is still using the deprecated FocusTrapFactory for now.

Issue Number: 5591

What is the new behavior?

Change back to FocusTrapFactory, which enables clicks outside overlay.

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 #5596 into master will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #5596      +/-   ##
==========================================
+ Coverage   87.70%   87.72%   +0.01%     
==========================================
  Files         458      458              
  Lines       13788    13788              
  Branches     2258     2258              
==========================================
+ Hits        12093    12095       +2     
+ Misses       1205     1204       -1     
+ Partials      490      489       -1     

Impacted Files	Coverage Δ
...ponents/modal/modal-confirm-container.component.ts	100.00% <ø> (ø)
components/modal/modal-container.component.ts	100.00% <ø> (ø)
components/drawer/drawer.component.ts	97.82% <100.00%> (ø)
components/modal/modal-container.ts	93.04% <100.00%> (ø)
components/core/util/text-measure.ts	91.30% <0.00%> (+1.73%)	⬆️

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[hsuanxyz]

LGTM