Support to specify Retype license key via input argument

[fabriciomurta]

The license, in general, should be stored as a secret;

important: remove/mask the license key as soon as the build completes to avoid leaking the license to subsequent steps

This feature likely depends on #1.

[fabriciomurta]

With #1 implemented, it was a simple change to add support to specify the license key via input parameters. Commit that introduces the actual change is efd0daa.