feedback: session replay integration

[armcknight]

Description

We do link any active session replay IDs, but I'm not sure about the 30 second thing that I noticed from the Javascript SDK docs while preparing the Cocoa SDK's docs: getsentry/sentry-docs#11191 (comment)

So, double check what currently happens, and if necessary, make the changes needed to bring it up to parity.

[armcknight]

It does look like we need to build an API for session replay to manually flush the buffer, then call that when the widget displays the form.