tsm-client: update URL structure
IBM has changed the URL structures of their support web pages.
The commit at hand updates most URLs and
in particular the package update instructions
so they follow the new structure.
It also calculates the source download URL from the
version number, so package updates no longer have to
update the URL in addition to the version string.
cherry-picked from https://github.com/NixOS/nixpkgs/pull/138386
