Add suite timeline to report

[nelson-q]

We are greatly missing the functionality of timelines and would appreciate it if you could add this feature.

Hypothetically, we have a test suite that runs in parallel across 5–10 threads:

To efficiently allocate resources, we need to know:

The duration of each thread
The execution order of tests within each thread and the duration of each test
The gap before a test starts (e.g., if a certain precondition is executed before it)
It’s also very convenient to visualize each thread as a horizontal timeline.

Having this information allows us to:

Distribute tests across different classes
Adjust the execution order
Optimize before methods to reduce pre-execution time, ensuring balanced execution times across threads.

Inefficient timeline: