fix(module: tree): update when property isLeaf is changed

[simplejason]

close #4037

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
[ ] 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
[ ] No

Other information

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[codecov]

Codecov Report

Merging #4289 into master will decrease coverage by <.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #4289      +/-   ##
==========================================
- Coverage   92.18%   92.17%   -0.01%     
==========================================
  Files         520      520              
  Lines       11011    11012       +1     
  Branches     1995     1995              
==========================================
  Hits        10150    10150              
- Misses        430      431       +1     
  Partials      431      431

Impacted Files	Coverage Δ
components/core/tree/nz-tree-base-node.ts	88.57% <0%> (-0.64%)	⬇️

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