Display results as HTML

Create a HTML view for the results.

The view should:
- [ ] display the current results
- [ ] display a history of results
- [ ] display a flame graph?

The current results are of type [`BenchmarkSummary`](https://github.com/atmoos/GlassView/blob/main/source/GlassView.Core/Models/BenchmarkSummary.cs). It should be possible to work with this type from memory, right after the export has been run.
To display a history, it should be possible to use the Renderer without running the exporter first. This means, it should be possible to import results from files.
Research what a flame graph is and how to display it based on the [`BenchmarkSummary`](https://github.com/atmoos/GlassView/blob/main/source/GlassView.Core/Models/BenchmarkSummary.cs).

Issue will be further refined as development continues.

Start with source/GlassView.Core/Models/BenchmarkSummary.cs, then trace the Renderer and exporter entry points. Determine how in-memory results and imported result files can feed the HTML view, and research how a flame graph could be derived from BenchmarkSummary. Done means the view supports current results, result history without rerunning the exporter, and an agreed decision on flame-graph support.

Written by the indexing model from the issue text.