Hover help with type information does not show column labels of relation types

[jurgenvinju]

Describe the bug

Here we see that the function imports returns a rel[str \module, str imported] but the hover help over the call to imports shows rel[str, str]

The labels are often nice to use later in the doc, and the hover help gives an added notion of discoverability of those labels for the programmer.

It would be a nice enhancement to make them available via this channel; this is not a bug.

Downstream inferred types of variables also have the labels (they work), but they are not shown either yet in the summaries.