feat(module:spin): support global indicator

[wzhudev]

close #2792

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: #2792

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[netlify]

Deploy preview for ng-zorro-master ready!

Built with commit 8b7185a

https://deploy-preview-4221--ng-zorro-master.netlify.com

[netlify]

Deploy preview for ng-zorro-master ready!

Built with commit dc3c2ec

https://deploy-preview-4221--ng-zorro-master.netlify.com

[codecov]

Codecov Report

Merging #4221 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #4221      +/-   ##
==========================================
+ Coverage   92.31%   92.32%   +<.01%     
==========================================
  Files         519      519              
  Lines       10963    10968       +5     
  Branches     1984     1984              
==========================================
+ Hits        10121    10126       +5     
- Misses        419      420       +1     
+ Partials      423      422       -1

Impacted Files	Coverage Δ
components/core/config/config.ts	100% <ø> (ø)	⬆️
components/spin/nz-spin.component.ts	100% <100%> (ø)	⬆️
components/typography/nz-typography.component.ts	97.93% <0%> (-1.04%)	⬇️
components/time-picker/time-holder.ts	97.36% <0%> (+0.87%)	⬆️

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[vthinkxie]

LGTM