Improve release branch version scripts

[t92549]

Rather than having to manually change Gaffer versions and open a separate PR, it would be nice if the create release branch action automatically changed them for you.
If you wanted a release that would change the docker script/helm chart app versions, but not the Gaffer version, you could append -patch1 to the release name and it would keep the Gaffer version the same but change the helm chart app version to include the patch number.