To display icons in explorer trees we can either pass a path or use resourceUri, there's no way to re-use icons used elsewhere in code for symbol types (for example in the workspace symbol searches).

This means that extensions with trees representing code have to ship their own icons (for ex. the "Code Outline" extension has its own: https://github.com/patrys/vscode-code-outline/tree/58008bfa3cc36ad2c18df53b2b4e53dc10a75d55/resources/light) which means they may not be consistent with the icons rendered elsewhere in code.

Is it possible to add something like a symbolKind: SymbolKind?