feat(module:slider): support nzTooltipPlacement

[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
[x] 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?

Users can set the default position of the tooltip by nzTooltipPlacement.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

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[codecov]

Codecov Report

Merging #4007 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #4007      +/-   ##
==========================================
+ Coverage   92.31%   92.33%   +0.02%     
==========================================
  Files         513      513              
  Lines       10796    10800       +4     
  Branches     1954     1955       +1     
==========================================
+ Hits         9966     9972       +6     
+ Misses        411      409       -2     
  Partials      419      419

Impacted Files	Coverage Δ
components/slider/nz-slider.component.ts	91.87% <100%> (+0.04%)	⬆️
components/slider/nz-slider-handle.component.ts	95.55% <100%> (+0.1%)	⬆️
...mponents/tooltip/base/nz-tooltip-base.directive.ts	90.81% <100%> (+1.12%)	⬆️
components/popconfirm/nz-popconfirm.directive.ts	100% <100%> (ø)	⬆️
...s/tooltip/base/nz-tooltip-base-legacy.component.ts	100% <0%> (+3.84%)	⬆️

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[wzhudev]

I don't know how I messed sliderwith progress. Please take care when merging this.