chore(module:tooltip,popover,popconfirm): refactor

[wzhudev]

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

Merging #4721 into master will increase coverage by 0.02%.
The diff coverage is 96%.

@@            Coverage Diff             @@
##           master    #4721      +/-   ##
==========================================
+ Coverage   93.22%   93.25%   +0.02%     
==========================================
  Files         506      503       -3     
  Lines       12757    12756       -1     
  Branches     1962     1960       -2     
==========================================
+ Hits        11893    11895       +2     
+ Misses        452      450       -2     
+ Partials      412      411       -1

Impacted Files	Coverage Δ
components/popover/popover.module.ts	100% <ø> (ø)
components/popconfirm/popconfirm.module.ts	100% <ø> (ø)
components/tooltip/tooltip.module.ts	100% <ø> (ø)
components/tooltip/tooltip.ts	100% <100%> (ø)
components/popconfirm/popconfirm.ts	100% <100%> (ø)
components/tooltip/base.ts	94.66% <93.05%> (ø)
components/popover/popover.ts	93.75% <93.75%> (ø)
components/typography/nz-typography.component.ts	98.23% <0%> (-0.89%)	⬇️
components/tree-select/nz-tree-select.component.ts	98.22% <0%> (-0.41%)	⬇️
components/radio/nz-radio-button.component.ts
... and 16 more

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