Version the `.curry/language-server` folder

We'd want to make sure that different versions of the language server can coexist, even if we make breaking changes to the ICurry format (e.g. as proposed in https://github.com/fwcd/curry-language-server/issues/26#issuecomment-1935329510).

Therefore we should include the language server version in the output directory path (e.g. `.curry/language-server-x.y.z`) and make sure this version number is bumped (at least) every time there is a breaking change in one of the serialized formats.

The issue names no files or tests. Start by locating where the `.curry/language-server` output path and serialized-format version are defined, then verify that versioned paths allow coexistence and that breaking format changes bump the version.

Written by the indexing model from the issue text.