feat(module:cascader): support nzPlacement

[Laffery]

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

[zorro-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

Attention: Patch coverage is 88.88889% with 2 lines in your changes missing coverage. Please review.

Project coverage is 91.90%. Comparing base (489e0de) to head (3d72570).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
components/cascader/cascader.component.ts	84.61%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8935      +/-   ##
==========================================
+ Coverage   91.86%   91.90%   +0.04%     
==========================================
  Files         555      555              
  Lines       19697    19709      +12     
  Branches     2940     2942       +2     
==========================================
+ Hits        18095    18114      +19     
+ Misses       1276     1268       -8     
- Partials      326      327       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[HyperLife1119]

LGTM