Attach breadcrumbs in error link when mutation fails with `errorPolicy: 'all'`

[durchanek]

I believe this has been mentioned in #420 When setting errorPolicy: 'all', no exception is raised but any error link set for apollo client will still execute with error details that can be sent to Sentry. This allows setting up Sentry integration globally, unlike throwing exceptions.
Unfortunately, it also means that error method of apollo-link-sentry is never called and breadcrumbs are not attached.