A logging query has a selector part and a regexp. The regexp matches are highlighted when results return.
This change adds live preview to matches when modifying the regexp in a search field.

- delegate retrieval of match query to datasource
- datasource returns search expressions to be used to highlight a live preview of matches
- logs row now takes preview highlights
- logs row renders preview highlights with dotted line to distinguish from query run matches (solid line)
- fix react-highlight-words version to ensure custom chunk matcher
- custom chunk matcher can now also take incomplete regexps, eg, `(level` without inifinte looping
- perf: debounce of live preview to 500ms
- perf: only top 100 rows get the live preview
- preview is only supported with one query row (multiple rows semantic makes this tricky: regexp for row n should only filter results for query n)