Feature Request : convert existing Change Set into new package-<change set name>.xml

[AltiusRupert]

As a VS Code user, I would like to be able to open VS Code SFDX Package Manager, look up the list of existing change sets in my project's org, select one of them, and automatically generate a package.xml manifest file named such as manifest/package-.xml

Every time I run this action, it would regenerate the same file, warning against conflicts with any unrecognized local changes. As an option, I could choose to generate a file named manifest/package.xml (or any other name) instead.

[AltiusRupert]

cc @jodieM