Global search should jump to an exact match, rather than just the line numberr

[nik-rev]

I looked into this, the current dependency used grep_searcher doesn't seem to provide any information on the start / end of a specific match. So I suppose it's not an "exact search" which potentially has performance improvements over exact search. Still, if the performance impact to use a more precise grep crate to jump to a character range instead of highlighting the entire line are negligible then I think this is worth considering.

I am talking about the global_search function in helix-term/src/commands.rs