fix(module:segmented): should render single element in item if icon-only

[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

[Nicoss54]

LGTM

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.21%. Comparing base (52322cd) to head (8d9dabb).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9363      +/-   ##
==========================================
- Coverage   92.25%   92.21%   -0.05%     
==========================================
  Files         561      561              
  Lines       19683    19680       -3     
  Branches     3015     3015              
==========================================
- Hits        18159    18148      -11     
- Misses       1192     1200       +8     
  Partials      332      332              

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[HyperLife1119]

This will cause the span element to be lost.

Expected behavior

Current behavior

[Laffery]

This will cause the span element to be lost.

Yes I also found this issue yesterday.

There seems to be no way to judge whether the ng-content contains content or not. Do you have any good suggestion about it?

---

From my perspective, I want to remove support for nzIcon if user customize the rendering template of nz-segmented-item in ng-content. Of course this brings breaking change:)

As compensation, we should add nzLabel property to nz-segmented-item, which accepts both string and TemplateRef types.

To be short, there are two individual ways for user to declare segmented items:

• nzIcon + nzLabel
• ng-content

WDYT?

[HyperLife1119]

I have a fix: #9367