Use DocumentSymbol interface for TextDocument::DocumentSymbol messages

[Slotos]

Preamble

Right now, Solargraph::LanguageServer::Message::TextDocument::DocumentSymbol implements SymbolInformation interface. This interface is deprecated to be replaced with DocumentSymbol one.

One of the benefits of DocumentSymbol interface is the inclusion of children property, which allows LSP clients to build tree-like structures, describing the code. Whereas SymbolInformation's containerName is explicitly defined to not be fit for that purpose.

Request

Use DocumentSymbol interface in Solargraph::LanguageServer::Message::TextDocument::DocumentSymbol implementation, with children property if possible.

[castwide]

Added to the roadmap.