This seems to be more consistent with how other LSPs work (like
`rust-analyzer`), and also I think is more consistent with how
`CompletionItem.detail` is itself rendered. Namely, in VS Code, it
is right-aligned. And it's also where we put the type signature.
But `CompletionItemLabelDetails.detail` is left-aligned where as
`CompletionItemLabelDetails.description` is right-aligned. So let's
swap them such that type signatures go in the latter and not the
former.
This also adds a space before the module name and contextualizes
it with `(import <name>)` to help aide the end user in figuring out
selecting the completion will do.
Fixes#1200
1ebbe73a1d