Highlight searched keyword in the history search
It would be more convenient for Spark to highlight the searched keyword in the history search. Especially as it now provides the context (previous and past lines) and it can be confusing.
Closing as fixed, though sometimes it doesn't highlight all the instances. Maybe it depends on the amount of messages or how recent the history is. Hard to test and reproduce. We can file another ticket if someone comes up with a good way to reproduce it.
There are still a few problems after the last PR.