User:Jdlrobson/Page issues analysis

In https://phabricator.wikimedia.org/T204143#4650771 we noted that we are seeing situation where PageIssues events are not matched with ReadingDepth.

This is my analysis.

Note Android doesn't show by default on caniuse - you have to turn it on by clicking "settings" and adding it explicitly.

For each combination, I considered RL, sendBeacon support and NavigationTimingSupport