perf(module:tabs): need add .ant-tabs-tab class reduce css computing …

[doxingg]

…time consuming(#7935)

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: #7935

What is the new behavior?

添加tabs组件路由联动中a标签的原本的父级div的class作为父级class，减少css需要计算时的范围，从而提升性能。

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[codecov]

Codecov Report

Merging #7936 (9a945b0) into master (59143d2) will not change coverage.
The diff coverage is n/a.

❗ Current head 9a945b0 differs from pull request most recent head 0fdbf42. Consider uploading reports for the commit 0fdbf42 to get more accurate results

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  Partials      299      299