reconsider starting debug adapters and language servers as raw processes

[akosyakov]

RawProcess is a process started by a user and should be executed with user env, e.g. tasks. Language servers and debug adapters (not debuggees) are not processes started by a user and should be executed with Theia (or own) env which can be different from user env, e.g. user-container vs Theia-container running side-by-side.

I think language servers and debug adapters should be spawned/forked with pure child_process module by default.

// cc @svenefftinge

[akosyakov]

Another point is to which processes the end user can have an access. For tasks it makes sense to give an access, but should the end user have access to language servers and debug adapters processes? Especially in the cloud case, when deploying and managing Theia is not the responsibility of end users.