Rename server-start.* to start.*, add sniff-start.bat

- git mv server-start.sh -> start.sh, server-start.bat -> start.bat
- Add Windows sniff-start.bat mirroring sniff-start.sh options
- Update usage comments and PWA help text references
- Bump 1.22.17, SW cache v48->v49

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'simtrace-analyser-v48';
+const CACHE = 'simtrace-analyser-v49';
 
 const PRECACHE = [
     'index.html',