add/remove label

[jtachikawa]

The "Update Build Info" API allows you to modify the label and favorite.
https://build-api.cloud.unity3d.com/docs/1.0.0/index.html#operation--orgs--orgid--projects--projectid--buildtargets--buildtargetid--builds--number--put

A function that attaches a label to the build result with the specified hash.
However, if a label has already been attached, an error will occur since only one label can be attached.

In addition, the build start subcommand will be updated to allow specifying labels at the same time.