Support for multiple hover targets under the cursor

[akaralar]

In Swift, a type can also be used as as an initializer (constructor) and the hover for Xcode returns both the type documentation and the documentation for the initializer.

let _ = URL(string: "http://example.com")
         ^
       request hover from cursor here

How these appear in Xcode are shown below.

Type hover doc

Initializer hover doc

Would it make sense for LSP to also support an array of Hover items as a response to the Hover request?

Also in the screenshots I shared, once the hover is presented, it's possible to switch between declarations shown at the top, so the top part acts somewhat like a "table of contents" of sorts for the resolved declarations. If multiple hover items are to be supported, it would be useful to have a field in Hover response for the resolved declaration, possibly of type MarkedString or MarkupContent.

[michaelpj]

This would be useful for HLS. We have multiple different pieces of information that we provide in hovers, and at the moment we just concatenate them all together with some headers. It's not terrible, but a more structured approach would be nice.