build: use ng-packagr to generate library

[trotyl]

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)
[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?

Switch to ng-packagr to build package which follows Angular Package Format 6.0.

Highlights:

• dependencies is not allowed by ng-packagr, only peerDependencies can be used;
• import * as pkg from 'pkg' are now import pkg from 'pkg';
• Root package.json no longer used to publish, only for dev purpose now;
• Package sub-path no longer contains the src segment;

Does this PR introduce a breaking change?

[x] Yes
[ ] No

CSS file imports require remove the /src segment.

Other information

[trotyl]

This should be enabled once our lib could pass it.

[codecov]

Codecov Report

Merging #1747 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master    #1747   +/-   ##
=======================================
  Coverage   96.07%   96.07%           
=======================================
  Files         466      466           
  Lines       11173    11173           
  Branches     1461     1461           
=======================================
  Hits        10735    10735           
  Misses        126      126           
  Partials      312      312

Impacted Files	Coverage Δ
components/tree/nz-tree.service.ts	95.19% <ø> (ø)	⬆️
components/calendar/nz-calendar.component.ts	100% <100%> (ø)	⬆️
...omponents/calendar/nz-calendar-header.component.ts	100% <100%> (ø)	⬆️
...omponents/date-picker/lib/candy-date/candy-date.ts	100% <100%> (ø)	⬆️
components/i18n/nz-i18n.service.ts	75.86% <100%> (ø)	⬆️

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[trotyl]

Previously I thought the import * as -> import default change could break type-checking without skipLibCheck or allowSyntheticDefaultImports, but turns out it would still be fine.

[trotyl]

Found the whitelistedNonPeerDependencies option which allows dependencies.

[vthinkxie]

Great, it seems that there are no break changes now.

[trotyl]

@vthinkxie The CSS path is still breaking, previously:

node_modules/ng-zorro-antd/src/ng-zorro-antd.min.css

Now:

node_modules/ng-zorro-antd/ng-zorro-antd.min.css

[vthinkxie]

@hsuanxyz please add back some shell scripts.