Reduce dependence on component.json

[nexustar]

Feature Request

Is your feature request related to a problem? Please describe:

tiup depends component.json not only when download components. When it meet error, lots of functiuon not work.

Describe the feature you'd like:

Reduce dependence on component.json

Why the featue is needed:

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: