[v10] Sample should happen after `beforeSend`

[buenaflor]

This issue is blocked for now as the decision to implement this is not finalized yet.

The main use case is that non-sampled errs should still update session health

Related: #3786

[linear-code]

DART-428

[Codel1417]

I use beforeSend to control if events should be sent to sentry, Wouldn't this send data even if all events were filtered?
Since my sample rates configured by a remote config file, setting sample rate during init is not an option for me, There is also a user option to disable sending events & traces.

[buenaflor]

this has no effect on your existing behaviour - beforeSend will still drop the events as you configured it. sample refers to events being filtered by the sampleRate in this case.