Should disable menu items like "Deploy" for external source windows

1)
```bicep
module automation_account 'br:sawbiceppublic.azurecr.io/sourcetest/avm/automation/automation-account:v1.0.1' = {
name: 'automation-account'
params: {}
}
```
2) Press F12 on the module path
3) click "View Bicep source (experimental)"
4) right-click in window -> Show deployment pane
(or Build ARM Template, etc)
!)

EXPECTED: All bicep source menus should be disabled for external source URIs

Reproduce the issue by opening the external module source with F12, choosing “View Bicep source (experimental),” and right-clicking to inspect the deployment pane and Build ARM Template actions. Trace the menu handling from that external-source window; done means all Bicep source menus are disabled for external source URIs.

Written by the indexing model from the issue text.