fix(module:cascader): menu closing behavoir

[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?

Cascader popover is not closed after clicking a none-leaf node when using nzChangeOnSelect and hover trigger, which is very misleading.

Issue Number: #6022

What is the new behavior?

Cascader popover is closed after clicking a none-leaf node when using nzChangeOnSelect and hover trigger

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

https://react-fvmcpb-2ij3hv.stackblitz.io
Both react and vue port of Ant Design works well

[codecov]

Codecov Report

Merging #6023 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #6023   +/-   ##
=======================================
  Coverage   89.95%   89.95%           
=======================================
  Files         465      465           
  Lines       14042    14042           
  Branches     2306     2307    +1     
=======================================
  Hits        12632    12632           
  Misses        863      863           
  Partials      547      547           

Impacted Files	Coverage Δ
components/cascader/cascader.component.ts	94.67% <100.00%> (ø)

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[wzhudev]

LGTM, thanks!