Third Party nodes not found when using global npm install

### Current Behavior

- https://discourse.nodered.org/t/dashboard-2-ui-led-not-displaying/94609/
- https://discourse.nodered.org/t/dashboard-2-custom-nodes-not-loading-when-installed-globally/94546/

### Expected Behavior

Given that Node-RED supports the global installation of nodes, Dashboard should too

### Steps To Reproduce

See attached Discourse topics

### Environment

- Dashboard version:
- Node-RED version:
- Node.js version:
- npm version:
- Platform/OS:
- Browser:

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate