refactor(): load configuration via same entry

[zanminkian]

As the commit msg, this PR is to let actions load nest-cli configuration via same entrance.

If you don't like it, please let me know. Thanks a lot.

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• 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)
[x] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

The attribute loader in BuildAction class is protected and I deleted it. Therefore, it may cause breaking change if third-party cli action has extended BuildAction.

[zanminkian]

If this PR is accepted, it will be easy to validate nest-cli.json. #692

We can validate it after it's loaded.

[kamilmysliwiec]

If this PR is accepted, it will be easy to validate nest-cli.json. #692
We can validate it after it's loaded.

Would you like to create a follow-up PR (using this PR as a base) to implement this feature?

[zanminkian]

If this PR is accepted, it will be easy to validate nest-cli.json. #692
We can validate it after it's loaded.

Would you like to create a follow-up PR (using this PR as a base) to implement this feature?

Sure. I will do this in 3 days.

[zanminkian]

@kamilmysliwiec New PR is #1427 . : )