Suggestion: "Last speed" should also indicate how many parallel threads were running last time

Last speed currently only shows a number, which is useless.

Ideally it should show the following:
- The number (and what it means)
- Number of parallel streams it was doing at that speed
- The test it is running (eg. 1080p h265 -> 1080p h264)

The issue does not name a file or test; start by locating the code that renders “Last speed” and trace the benchmark result data it receives. Confirm how the speed, parallel stream count, and transcoding test are represented, then verify that all three appear together in the displayed result.

Written by the indexing model from the issue text.