Version Manager (Builtin)

[emil14]

It would be nice to have something like nvm out of the box. One use-case is when you reinstall the language to run e2e tests locally, but then would like to switch back to release version. The API can be minimal - just one use command that will install (if needed) and switch the version

neva use 0.31.0 // or v0.31.0

The only concern is that we can switch to version that doesn't have version manager