type alias tooltips don't appear, not shown correctly in the info panel

```
type StringPair = string * string

let pairs : StringPair list = [ "", "" ]
```
StringPair does appear during mouseover on `pairs` and the line lens shows it at the end. Mouseover on `StringPair` does nothing (visually) and prints this in the log:

> [10:13:45.200 INF] [LSP] TextDocumentHover Request: {"TextDocument": {"Uri": "file:.../test.fs", "$type": "TextDocumentIdentifier"}, "Position": {"Line": 3, "Character": 19, "$type": "Position"}, "$type": "TextDocumentPositionParams"}
> [10:13:45.201 INF] [Checker] TryGetRecentCheckResultsForFile - "...\test.fs"
> [Error - 10:13:45 AM] Request textDocument/hover failed.
> Message: No tooltip information
> Code: -32603

The info panel doesn't seem to recognize it.

In the module view, it has a link but nothing happens when clicked except:
> [11:18:47.224 INF] [LSP] FSharpDocumentationSymbol Request: {"XmlSig": "T:Test.StringPair", "Assembly": "test", "$type": "DocumentationForSymbolReuqest"}