This PR should improve performance when opening large workflows that
contain node issues (Fixes ADO-1521)
**Background**
Main reason for this poor performance is that our `getCurrentWorkflow()`
store getter is unnecessarily heavy but on top of that we are calling it
more than we need. This addresses the second part of the issue by
changing the following:
- Pausing node issue processing while workflows are loading
- Only getting current workflow once (instead for every node) when
calling `refreshNodeIssues`
**Benchmark**
This was tested on a workflow attached to [this Linear
ticket](https://linear.app/n8n/issue/ADO-1501/deliveryhero-enterprise-instance-very-slow-loading-workflows)
and this fix brings down opening time from **~1m10s** to **~28s** on my
laptop.
**Tests**
- [Latest e2e tests
run](https://github.com/n8n-io/n8n/actions/runs/7060874994)
https://community.n8n.io/t/ui-very-slow-with-more-than-100-nodes/8236/14
Github issue / Community forum post (link here to close automatically):
https://github.com/n8n-io/n8n/pull/6348
---------
Co-authored-by: Giulio Andreini <g.andreini@gmail.com>
Co-authored-by: Marcus <marcus@n8n.io>
