Command "traces.openTraceFile" - should it be available from command palette?

ATM command "traces.openTraceFile" (label: "Open with Trace Viewer") is available in the command palette. However it seems to only work when triggered from the explorer's context menu, with a file selection. If triggered from the command palette, it seems to always fail, even if one selects the file before invocation. Should it even be available from the command palette?

The error message is rather cryptic too:


Maybe we could register the command using the "when" clause and use contexts to make it available only when appropriate. Here are some contexts that could potentially be used, with example values, when a trace file is selected in the explorer:
```
"focusedView": "workbench.explorer.fileView",
"workbench.explorer.fileView.active": true,
"resource": "file:///home/user/TraceCompassTutorialTraces/303-jaeger-opentracing-traces/donutJaegerTrace.json",
"resourceScheme": "file",
"resourceFilename": "donutJaegerTrace.json",
"workbench.explorer.fileView.active": true,
"explorerResourceIsFolder": false,
"filesExplorerFocus": true,
```

Failing that, we could at least adjust the error message to say how that command should be triggered?