[DAP] `--pause-isolates-on-start` flag is not respected for web refreshes

[elliette]

Unlike VM apps, web apps can both be hot-restarted and restarted via a page-refresh. When they are restarted with a page refresh, the readyToResume request is never sent after the breakpoints are set, and so if --pause-isolates-on-start is set, the app never gets resumed.

FYI @DanTup - I have a fix prepared that I will send out shortly.

[elliette]

This is also occurring on a hot-restart request