Add regex filter support

This makes any filter that starts and ends in forward slashes act as a
regex filter instead of a simple substring filter.

Currently doesn't support trailing flags unlike actual JS regexes, so
modifiers should be used instead for that functionality:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Regular_expressions/Modifier

src/services/status_parser/status_parser.js

@@ -4,6 +4,10 @@ export const muteWordHits = (status, muteWords) => {
   const statusText = status.text.toLowerCase()
   const statusSummary = status.summary.toLowerCase()
   const hits = filter(muteWords, (muteWord) => {
+    if (muteWord.startsWith('/') && muteWord.endsWith('/')) {
+      const muteRegex = new RegExp(muteWord.slice(1, -1))
+      return muteRegex.test(statusText) || muteRegex.test(statusSummary)
+    }
     return statusText.includes(muteWord.toLowerCase()) || statusSummary.includes(muteWord.toLowerCase())
   })