Fix differences with events in CDP collector
Fix differences with events in CDP collector

Send `targetfetch::start` and `targetfetch::stop` when `sonar` starts
and finishes loading the main target (taking into account redirects),
and `fetch::start` and `fetch::stop` when resources such as JS and CSS
are downlaoded (previously it was `targetfetch::start` and `fetch::end`
for any download).

alrra/sonar,sonarwhal/sonar,alrra/sonar,sonarwhal/sonar,alrra/sonar,sonarwhal/sonar