perf(module:select): ability to pass key | nzKey to select option

[oleksandr-codefresh]

When 'object' is used as 'value' for select option re-rendering occurs each time data comes, to solve this added new 'key' param | 'nzKey' Input

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
[x] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Under the hood nz-select uses value | nzValue as key for rendering optimizations. In case if value of 'object' type this doesn't work well.

Issue Number: #8034

What is the new behavior?

We use value as fallback and allow passing key | nzKey for this specific purpose

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 #8033 (2785f5f) into master (544f308) will decrease coverage by 0.01%.
Report is 2 commits behind head on master.
The diff coverage is 70.00%.

❗ Current head 2785f5f differs from pull request most recent head bc4cf48. Consider uploading reports for the commit bc4cf48 to get more accurate results

@@            Coverage Diff             @@
##           master    #8033      +/-   ##
==========================================
- Coverage   91.64%   91.64%   -0.01%     
==========================================
  Files         515      515              
  Lines       17637    17642       +5     
  Branches     2789     2792       +3     
==========================================
+ Hits        16164    16168       +4     
+ Misses       1175     1174       -1     
- Partials      298      300       +2     

Files Changed	Coverage Δ
components/select/option.component.ts	100.00% <ø> (ø)
components/tree/tree-node.component.ts	92.43% <ø> (+0.49%)	⬆️
components/select/select.component.ts	92.09% <33.33%> (-0.51%)	⬇️
components/qr-code/qrcode.component.ts	90.69% <85.71%> (-1.62%)	⬇️

... and 1 file with indirect coverage changes

[oleksandr-codefresh]

@vthinkxie pls review once you will be able, thx)

[oleksandr-codefresh]

@hsuanxyz Hi, maybe you can review? thx)

[hsuanxyz]

@simplejason check this plz.

[hsuanxyz]

@oleksandr-codefresh can we change the commit type to perf

[oleksandr-codefresh]

@hsuanxyz yes, changed it

[oleksandr-codefresh]

@simplejason @vthinkxie @hsuanxyz pls, review when it's possible for you 🙏

[hsuanxyz]

LGTM

[oleksandr-codefresh]

@OriginRing Hi, could you pls add label 'PR: reviewed-approved' to pr?