Explore: Logging query live preview of matches

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)

package.json

@@ -108,18 +108,9 @@
     "precommit": "lint-staged && grunt precommit"
   },
   "lint-staged": {
-    "*.{ts,tsx}": [
-      "prettier --write",
-      "git add"
-    ],
-    "*.scss": [
-      "prettier --write",
-      "git add"
-    ],
-    "*pkg/**/*.go": [
-      "gofmt -w -s",
-      "git add"
-    ]
+    "*.{ts,tsx}": ["prettier --write", "git add"],
+    "*.scss": ["prettier --write", "git add"],
+    "*pkg/**/*.go": ["gofmt -w -s", "git add"]
   },
   "prettier": {
     "trailingComma": "es5",
@@ -156,7 +147,7 @@
     "react-custom-scrollbars": "^4.2.1",
     "react-dom": "^16.5.0",
     "react-grid-layout": "0.16.6",
-    "react-highlight-words": "^0.10.0",
+    "react-highlight-words": "0.11.0",
     "react-popper": "^0.7.5",
     "react-redux": "^5.0.7",
     "react-select": "2.1.0",