Feature/n8n 2835 handle error workflows correctly

[krynble]

This PR needs to be merged AFTER #2697 as it relies on many changes made by it.

• Adds runtime checks for the Error workflow feature, where you can select another workflow to be executed upon a workflow error.

This can happen in two different ways:

1. Select another workflow from the current workflow settings to be executed on error. This secondary workflow needs to contain the Error trigger node
2. A single workflow contains a trigger path and also the Error trigger node in itself, like self-healing.

The checks were implemented only for situation (1) as (2) doesn't make sense to check ownership for the workflow itself. Also, instance owners bypass this check.

[krynble]

Closing in favor of #2908