Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1664
The various filtering engine benchmarking functions are best
isolated in their own file since they have specific
dependencies that should not be suffered by the filtering
engines.
Additionally, moved decomposeHostname() into uri-utils.js
as it's a hostname-related function required by many
filtering engine cores -- this allows to further reduce
or outright remove dependency on `µb`.