Feat: Support version tags

[marvinhagemeister]

Releasing a package with multiple release lines is difficult at the moment, because you need to tell users the exact version string. Npm has the tags feature that allow you to tag release lines with the default one being @latest.

Example: To use the Fresh 2 alpha we need to tell users to do this:

deno run -Ar jsr:@fresh/init@2.0.0-alpha.33

What we would like to do:

deno run -Ar jsr:@fresh/init@alpha

With being forced to use the exact version string we always need to update all the places where we have this command to stay current.

Related #382

[lishaduck]

But please don't make Deno commit that, just make it a cli shorthand; it's a pain in the rolldown ecosystem when packages use "canary" and then lockfiles aren't deterministic anymore.