domains: fix issues with abort on uncaught

Do not abort the process if an error is thrown from within a domain, an
error handler is setup for the domain and --abort-on-uncaught-exception
was passed on the command line.

However, if an error is thrown from within the top-level domain's error
handler and --abort-on-uncaught-exception was passed on the command
line, make the process abort.

Fixes #8631. Also fixes #8630.
Sure you need all the double checking? Should be enough to simply: `return domain_v->IsObject();`

But... I can't remember the nuances of the v0.10 V8 API.