Enhancement: Add option to catalog generate to explicitly set release-dir

[jspaleta]

The problem

Right now catalog generate supported generating into a randomly named temp dir and then uses github action specific stdout text to communicate the randomly named directory and save it as release-dir for other github actions to use.

But this makes it hard to support private catalog use cases that use other CI/CD based workflows other than github actions.

Straw proposal

add a new argument to generate to specify the temp dir subdirectory name instead of using a random name. Default to using random if not specified.

This would allow other CI/CD workflows to explictly specify the full release directory path as an input to the api generate command instead of having to discover what it is via stdout scraping.V