build: add inline step for templateUrl

[trotyl]

closes #684

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
[x] 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: #684

What is the new behavior?

Enable using templateUrl for components.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

Only made change for button here since it's covered by integration tests. Others can be done in follow ups.

[coveralls]

Coverage remained the same at 40.856% when pulling 6400ed1 on trotyl:separate-template into bda29de on NG-ZORRO:master.