Allow setting queue-processing to be managed per-form, and per-integration

[engram-design]

Our use-case is for User Element integrations. Because these are run via the queue, autoLoginAfterAccountActivation fails to work. The only solution is to disable the queue processing.

But rather than have this set site-wide, where other integrations are detrimentally effected by this change, I'd propose being able to change whether an integration runs on the queue or not configured at the form. We'd still keep the plugin-wide setting as the default. I'd also not like to have an option just for User element integrations, as I'm sure there might be other cases where integrations would want to be run off-queue.

Related craftcms/cms#7294

[simonleadbetter]

We’ve been building a registration form for a membership website, which has multiple integrations (Salesforce, MailChimp and User Element). Ideally, we would like the option to configure each integration as we only need the User Element integration to bypass the default queue. This would allow us to still benefit from the performance gains of having the Salesforce and Mailchimp being handled by the queue.

[Mosnar]

Just wanted to highlight this since I just ran into it again. I have a form that needs to post some data to a third-party service before redirecting the user, so doing it in the queue is a no-go.