fix(module:cascader): fix support to nzLabelProperty

[wzhudev]

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
[x] 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?

Lack of support to nzLabelProperty.

Issue Number: #2103

What is the new behavior?

Would search nzLabelProperty when it's specified.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[codecov]

Codecov Report

Merging #2231 into master will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2231      +/-   ##
==========================================
+ Coverage   95.88%   95.92%   +0.03%     
==========================================
  Files         485      485              
  Lines       12182    12184       +2     
  Branches     1638     1639       +1     
==========================================
+ Hits        11681    11687       +6     
+ Misses        143      142       -1     
+ Partials      358      355       -3

Impacted Files	Coverage Δ
components/cascader/nz-cascader.component.ts	96.74% <100%> (+0.18%)	⬆️
components/table/nz-table.component.ts	95.55% <0%> (+1.66%)	⬆️

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