feat(module:schematics): align with the updated style guide

[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

在 Angular v20 更新的风格指南中，新项目默认 app.ts 等文件不带有 component 扩展名，这导致基于 ng-zorro-antd 的 schematics 模板生成的代码与之不匹配。

What is the new behavior?

• 对齐 Angular v20 更新的风格指南，支持指定 ng-component 的 type ngHtml 等扩展名配置项，以及 skipSelector exportDefault 配置项
• ng-add 新增可选模板 topnav

Does this PR introduce a breaking change?

• Yes
• No

Other information

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.08%. Comparing base (add21f7) to head (5a1c30c).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9295      +/-   ##
==========================================
- Coverage   92.12%   92.08%   -0.05%     
==========================================
  Files         561      561              
  Lines       19627    19627              
  Branches     3106     3106              
==========================================
- Hits        18082    18074       -8     
- Misses       1206     1214       +8     
  Partials      339      339              

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[Laffery]

本地测试有点问题，处理中

[Laffery]

本地测试有点问题，处理中

问题已修复，本地 CLI 运行测试通过

[HyperLife1119]

LGTM