chore: add license header to harbor cli project

[amands98]

Add license header to harbor cli just like we have for harbor project.

[Vad1mo]

thats good, but we need to automate the adding of it to each header of the file or check it before each commit or in the CI, disallowing the merge

[bupd]

then, We can add a workflow to check for headers in every file.

[Vad1mo]

we need a more consistant approch to make sure headers are set or not set them at all.

Some examples:

• https://github.com/palantir/go-license