cgroup collection html output by container is missing

When perfspect is collected using cgroup scope, the html output still shows system level data since it aggregates the raw metrics into the html. Can we extend another tab to show per container results in the html? The raw data is already present in the json and csv files, its a matter of display.
This is based on:
```
Ubuntu 22.04
Kernel 6.8
perfspect version 3.14
```

Start by tracing the HTML generation and comparing it with the existing JSON and CSV output, where per-container raw metrics are already present. Identify how the current system-level aggregation feeds the HTML and add a separate container-results tab. Done means cgroup-scope reports display per-container results in HTML while retaining the existing system-level view.

Written by the indexing model from the issue text.