che: Theia should not offer to start apps for debugging

Is your enhancement related to a problem? Please describe.

Many default suggested debug configurations in Theia operate similarly to VSCode: they start the specified app and connect debugging to it.

This does not make sense for Eclipse Che. We often start the Theia sidecar container with a limited (512MiB) memory quota, and often it’s impossible to run anything else significant in this container.

Some examples that come to mind are

1. The netcoredbg plugin for .NET workspaces only seems to work locally, so the application has to start in a sidecar container
2. The built-in autocompletes for debug configurations include “launch” configs, which call e.g. npm debug in the theia container; these usually get killed before starting up completely

Describe the solution you’d like

At the very least, Theia should not suggest configurations that will not work. Ideally Theia would be able to somehow operate in the main workspace container (which should have enough memory to run the app), but I realize this is likely not possible in a general way.

Describe alternatives you’ve considered

Caveat emptor, I guess?

Additional context