CI/CD

Show error message when creation of customization failed on server #603

Job	Run time
Run linter (ubuntu-latest)	1m 18s
Build & run UI Tests (ubuntu-latest, node-18)	3m 35s
Build & run UI Tests (ubuntu-latest, node-20)	4m 4s
Build & run UI Tests (ubuntu-latest, node-22)	3m 12s
Publish extension to public Open VSX Registry	0s
Publish extension to Visual Studio Marketplace	0s
	12m 9s

Provide feedback