[dotnet-trace] Convert and Report not compatible with collect-linux traces

Traces generated by `collect-linux` in https://github.com/dotnet/diagnostics/pull/5570 do not collect samples from `Microsoft-DotNETCore-SampleProfiler`. `dotnet-trace convert` and `dotnet-trace report` both generate thread time stacks assuming samples from SampleProfiler https://github.com/dotnet/diagnostics/blob/fcb028b0c776e72f2cdaa9b4a841dd69e72f6bf0/src/Tools/dotnet-trace/TraceFileFormatConverter.cs#L81-L85 and https://github.com/dotnet/diagnostics/blob/fcb028b0c776e72f2cdaa9b4a841dd69e72f6bf0/src/Tools/dotnet-trace/CommandLine/Commands/ReportCommand.cs#L56-L58, so both verbs will result in empty thread time stacks.

Instead, `collect-linux` can collect thread time perf_event samples with `--profile thread-time`. So to add support for the new collect-linux traces, `convert` and `report` should probably be updated to use https://github.com/microsoft/perfview/blob/main/src/TraceEvent/Computers/ThreadTimeComputer.cs when that's released