feat(compiler): add noBuild option

[vicary]

What did you implement:

Closes #965

I removed the --no-build CLI option from README to discourage usage, the actual feature is kept for backward compatibility.

How did you implement it:

custom:
  webpack:
    noBuild: true

How can we verify it:

> serverless deploy
> serverless invoke local
> serverless offline

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Make sure code coverage hasn't dropped
• Provide verification config / commands / resources
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO

[j0k3r]

👍