Devfile API repo missing license header

[yangcao77]

Which area/kind this issue is related to?

/area ci
/area api

Issue Description

code under devfile/api are missing license header.
this issue is expecting all files have license added, and similar as other repos, create script to auto-adding the header, and also create a check in CI

Acceptance Criteria

• All files have license added
• Create script to auto-adding the header
• Create a check in CI

refined by: @michael-valdron

[github-actions]

This issue is stale because it has been open for 90 days with no activity. Remove stale label or comment or this will be closed in 60 days.