Elsa 3 - Allow the user to manually select the desired sub-workflow version

Currently, if you use a sub-workflow in your main workflow, you start with the latest version of the sub-workflow. Once you make a change to the workflow, your main workflow will either be automatically updated or will keep using the same version (this depends of whether you enabled auto-update or not).

However, if you didn't enable the auto-update, and there were a couple of new versions of the sub-workflow, in your main workflow you don't have the possibility to select a specific version. What you can do is just press the update button that will select the latest version.

It would be great if the user would have the possibility to select a specific version, maybe through a dropdown. This will improve the maintainability of the workflow.

Why is this desired, a workflow may need to use an earlier version of a sub-workflow while another workflow may need to use the latest version.