build: add noUnusedLocals config

[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

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)
[x] 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?

Add noUnusedLocals to tsconfig.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[wzhudev]

I will update code style in this sequence of pull requests too.

Please merge these pull requests as quickly as possible. Otherwise I have to rebase a lot of times...

[netlify]

Deploy preview for ng-zorro-master ready!

Built with commit 87e7cab

https://deploy-preview-2959--ng-zorro-master.netlify.com

[codecov]

Codecov Report

Merging #2959 into master will decrease coverage by <.01%.
The diff coverage is 92.59%.

@@            Coverage Diff             @@
##           master    #2959      +/-   ##
==========================================
- Coverage   97.35%   97.35%   -0.01%     
==========================================
  Files         529      529              
  Lines       11094    11081      -13     
  Branches      803      803              
==========================================
- Hits        10801    10788      -13     
  Misses        183      183              
  Partials      110      110

Impacted Files	Coverage Δ
components/drawer/nz-drawer.component.ts	100% <ø> (ø)	⬆️
components/anchor/nz-anchor-link.component.ts	100% <ø> (ø)	⬆️
components/modal/nz-modal.component.ts	99.5% <ø> (-0.01%)	⬇️
components/tag/nz-tag.component.ts	100% <ø> (ø)	⬆️
components/message/nz-message.service.ts	97.91% <ø> (ø)	⬆️
...omponents/calendar/nz-calendar-header.component.ts	100% <ø> (ø)	⬆️
components/slider/nz-slider-handle.component.ts	100% <ø> (ø)	⬆️
components/calendar/nz-calendar.component.ts	97.27% <ø> (-0.02%)	⬇️
...ents/time-picker/nz-time-picker-panel.component.ts	92.39% <ø> (ø)	⬆️
components/empty/nz-embed-empty.component.ts	95.91% <ø> (ø)	⬆️
... and 26 more

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[vthinkxie]

LGTM