Type-aware autocompletion

Hi, I'm surprised that I couldn't find a similar issue, except for https://github.com/haskell/haskell-language-server/issues/817. Please excuse me if it is misplaced.

I wish HLS provided type-aware autocompletion. The autocompletion it does have often isn't very useful:

In this case, the obvious type-correct autocompletion would be `ssDynTrace`, of type `[DynTraceEntry]`. Instead, the autocompletion is full of relevant but quite useless definitions. In fact, `ssDynTrace` isn't even listed until I type a `d`.

Another issue is that with record wildcards, there are duplicate completions available. Here, `ssDynTrace` is listed once as the value from the wildcard and once more as the getter function.

In theory, I could use a hole instead, but invoking Wingman with many bindings in scope isn't a good idea:

Even if VS Code made the quick action list searchable, the "attempt to fill hole" and "refine hole" commands time out. Plus, Wingman doesn't seem like the right tool for the job – I know pretty well what I want to write, I just don't want to have to spell every identifier out, and the types involved don't uniquely identify the correct solution.

It'd be nice if HLS could trim the autocompletion suggestions by type and offer relevant suggestions even with no prior identifier input.